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  Subjects -> CHEMISTRY (Total: 841 journals)
    - ANALYTICAL CHEMISTRY (50 journals)
    - CHEMISTRY (593 journals)
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CHEMISTRY (593 journals)                  1 2 3 | Last

Showing 1 - 200 of 735 Journals sorted alphabetically
2D Materials     Hybrid Journal   (Followers: 8)
Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement     Hybrid Journal   (Followers: 26)
ACS Catalysis     Full-text available via subscription   (Followers: 34)
ACS Chemical Neuroscience     Full-text available via subscription   (Followers: 18)
ACS Combinatorial Science     Full-text available via subscription   (Followers: 23)
ACS Macro Letters     Full-text available via subscription   (Followers: 23)
ACS Medicinal Chemistry Letters     Full-text available via subscription   (Followers: 39)
ACS Nano     Full-text available via subscription   (Followers: 233)
ACS Photonics     Full-text available via subscription   (Followers: 11)
ACS Synthetic Biology     Full-text available via subscription   (Followers: 21)
Acta Chemica Iasi     Open Access   (Followers: 2)
Acta Chimica Sinica     Full-text available via subscription   (Followers: 1)
Acta Chimica Slovaca     Open Access   (Followers: 1)
Acta Chromatographica     Full-text available via subscription   (Followers: 9)
Acta Facultatis Medicae Naissensis     Open Access  
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 5)
Acta Scientifica Naturalis     Open Access   (Followers: 2)
adhäsion KLEBEN & DICHTEN     Hybrid Journal   (Followers: 5)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 7)
Adsorption Science & Technology     Full-text available via subscription   (Followers: 5)
Advanced Functional Materials     Hybrid Journal   (Followers: 50)
Advanced Science Focus     Free   (Followers: 3)
Advances in Chemical Engineering and Science     Open Access   (Followers: 55)
Advances in Chemical Science     Open Access   (Followers: 13)
Advances in Chemistry     Open Access   (Followers: 14)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 18)
Advances in Drug Research     Full-text available via subscription   (Followers: 22)
Advances in Enzyme Research     Open Access   (Followers: 9)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 15)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 8)
Advances in Materials Physics and Chemistry     Open Access   (Followers: 19)
Advances in Nanoparticles     Open Access   (Followers: 15)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 15)
Advances in Polymer Science     Hybrid Journal   (Followers: 41)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 18)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 19)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 5)
Advances in Science and Technology     Full-text available via subscription   (Followers: 12)
African Journal of Bacteriology Research     Open Access  
African Journal of Chemical Education     Open Access   (Followers: 2)
African Journal of Pure and Applied Chemistry     Open Access   (Followers: 7)
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 2)
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 3)
AMB Express     Open Access   (Followers: 1)
Ambix     Hybrid Journal   (Followers: 3)
American Journal of Biochemistry and Biotechnology     Open Access   (Followers: 68)
American Journal of Biochemistry and Molecular Biology     Open Access   (Followers: 14)
American Journal of Chemistry     Open Access   (Followers: 26)
American Journal of Plant Physiology     Open Access   (Followers: 14)
American Mineralogist     Hybrid Journal   (Followers: 14)
Analyst     Full-text available via subscription   (Followers: 40)
Angewandte Chemie     Hybrid Journal   (Followers: 222)
Angewandte Chemie International Edition     Hybrid Journal   (Followers: 213)
Annales UMCS, Chemia     Open Access   (Followers: 1)
Annals of Clinical Chemistry and Laboratory Medicine     Open Access   (Followers: 3)
Annual Reports in Computational Chemistry     Full-text available via subscription   (Followers: 3)
Annual Reports Section A (Inorganic Chemistry)     Full-text available via subscription   (Followers: 4)
Annual Reports Section B (Organic Chemistry)     Full-text available via subscription   (Followers: 8)
Annual Review of Chemical and Biomolecular Engineering     Full-text available via subscription   (Followers: 12)
Annual Review of Food Science and Technology     Full-text available via subscription   (Followers: 15)
Anti-Infective Agents     Hybrid Journal   (Followers: 3)
Antiviral Chemistry and Chemotherapy     Hybrid Journal  
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 7)
Applied Spectroscopy     Full-text available via subscription   (Followers: 23)
Applied Surface Science     Hybrid Journal   (Followers: 28)
Arabian Journal of Chemistry     Open Access   (Followers: 6)
ARKIVOC     Open Access   (Followers: 2)
Asian Journal of Biochemistry     Open Access   (Followers: 1)
Atomization and Sprays     Full-text available via subscription   (Followers: 4)
Australian Journal of Chemistry     Hybrid Journal   (Followers: 7)
Autophagy     Hybrid Journal   (Followers: 2)
Avances en Quimica     Open Access   (Followers: 1)
Biochemical Pharmacology     Hybrid Journal   (Followers: 10)
Biochemistry     Full-text available via subscription   (Followers: 295)
Biochemistry Insights     Open Access   (Followers: 6)
Biochemistry Research International     Open Access   (Followers: 6)
BioChip Journal     Hybrid Journal  
Bioinorganic Chemistry and Applications     Open Access   (Followers: 9)
Bioinspired Materials     Open Access   (Followers: 5)
Biointerface Research in Applied Chemistry     Open Access   (Followers: 2)
Biointerphases     Open Access   (Followers: 1)
Biology, Medicine, & Natural Product Chemistry     Open Access   (Followers: 1)
Biomacromolecules     Full-text available via subscription   (Followers: 19)
Biomass Conversion and Biorefinery     Partially Free   (Followers: 10)
Biomedical Chromatography     Hybrid Journal   (Followers: 6)
Biomolecular NMR Assignments     Hybrid Journal   (Followers: 3)
BioNanoScience     Partially Free   (Followers: 4)
Bioorganic & Medicinal Chemistry     Hybrid Journal   (Followers: 121)
Bioorganic & Medicinal Chemistry Letters     Hybrid Journal   (Followers: 98)
Bioorganic Chemistry     Hybrid Journal   (Followers: 10)
Biopolymers     Hybrid Journal   (Followers: 18)
Biosensors     Open Access   (Followers: 2)
Biotechnic and Histochemistry     Hybrid Journal   (Followers: 1)
Bitácora Digital     Open Access  
Boletin de la Sociedad Chilena de Quimica     Open Access  
Bulletin of the Chemical Society of Ethiopia     Open Access   (Followers: 2)
Bulletin of the Chemical Society of Japan     Full-text available via subscription   (Followers: 24)
Bulletin of the Korean Chemical Society     Hybrid Journal   (Followers: 1)
C - Journal of Carbon Research     Open Access   (Followers: 3)
Cakra Kimia (Indonesian E-Journal of Applied Chemistry)     Open Access  
Canadian Association of Radiologists Journal     Full-text available via subscription   (Followers: 3)
Canadian Journal of Chemistry     Hybrid Journal   (Followers: 10)
Canadian Mineralogist     Full-text available via subscription   (Followers: 3)
Carbohydrate Research     Hybrid Journal   (Followers: 26)
Carbon     Hybrid Journal   (Followers: 66)
Catalysis for Sustainable Energy     Open Access   (Followers: 7)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 8)
Catalysis Science and Technology     Free   (Followers: 6)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysts     Open Access   (Followers: 8)
Cellulose     Hybrid Journal   (Followers: 7)
Cereal Chemistry     Full-text available via subscription   (Followers: 4)
ChemBioEng Reviews     Full-text available via subscription   (Followers: 1)
ChemCatChem     Hybrid Journal   (Followers: 8)
Chemical and Engineering News     Free   (Followers: 13)
Chemical Bulletin of Kazakh National University     Open Access  
Chemical Communications     Full-text available via subscription   (Followers: 70)
Chemical Engineering Research and Design     Hybrid Journal   (Followers: 23)
Chemical Research in Chinese Universities     Hybrid Journal   (Followers: 3)
Chemical Research in Toxicology     Full-text available via subscription   (Followers: 19)
Chemical Reviews     Full-text available via subscription   (Followers: 176)
Chemical Science     Open Access   (Followers: 22)
Chemical Technology     Open Access   (Followers: 16)
Chemical Vapor Deposition     Hybrid Journal   (Followers: 5)
Chemical Week     Full-text available via subscription   (Followers: 8)
Chemie in Unserer Zeit     Hybrid Journal   (Followers: 57)
Chemie-Ingenieur-Technik (Cit)     Hybrid Journal   (Followers: 26)
ChemInform     Hybrid Journal   (Followers: 8)
Chemistry & Biodiversity     Hybrid Journal   (Followers: 6)
Chemistry & Biology     Full-text available via subscription   (Followers: 30)
Chemistry & Industry     Hybrid Journal   (Followers: 5)
Chemistry - A European Journal     Hybrid Journal   (Followers: 142)
Chemistry - An Asian Journal     Hybrid Journal   (Followers: 15)
Chemistry and Materials Research     Open Access   (Followers: 18)
Chemistry Central Journal     Open Access   (Followers: 4)
Chemistry Education Research and Practice     Free   (Followers: 5)
Chemistry in Education     Open Access   (Followers: 9)
Chemistry International     Hybrid Journal   (Followers: 2)
Chemistry Letters     Full-text available via subscription   (Followers: 44)
Chemistry of Materials     Full-text available via subscription   (Followers: 258)
Chemistry of Natural Compounds     Hybrid Journal   (Followers: 9)
Chemistry World     Full-text available via subscription   (Followers: 22)
Chemistry-Didactics-Ecology-Metrology     Open Access   (Followers: 1)
ChemistryOpen     Open Access   (Followers: 2)
Chemkon - Chemie Konkret, Forum Fuer Unterricht Und Didaktik     Hybrid Journal  
Chemoecology     Hybrid Journal   (Followers: 3)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 15)
Chemosensors     Open Access  
ChemPhysChem     Hybrid Journal   (Followers: 9)
ChemPlusChem     Hybrid Journal   (Followers: 2)
ChemTexts     Hybrid Journal  
CHIMIA International Journal for Chemistry     Full-text available via subscription   (Followers: 2)
Chinese Journal of Chemistry     Hybrid Journal   (Followers: 6)
Chinese Journal of Polymer Science     Hybrid Journal   (Followers: 10)
Chromatographia     Hybrid Journal   (Followers: 24)
Clay Minerals     Full-text available via subscription   (Followers: 10)
Cogent Chemistry     Open Access  
Colloid and Interface Science Communications     Open Access  
Colloid and Polymer Science     Hybrid Journal   (Followers: 10)
Colloids and Surfaces B: Biointerfaces     Hybrid Journal   (Followers: 7)
Combinatorial Chemistry & High Throughput Screening     Hybrid Journal   (Followers: 4)
Combustion Science and Technology     Hybrid Journal   (Followers: 18)
Comments on Inorganic Chemistry: A Journal of Critical Discussion of the Current Literature     Hybrid Journal   (Followers: 2)
Composite Interfaces     Hybrid Journal   (Followers: 6)
Comprehensive Chemical Kinetics     Full-text available via subscription   (Followers: 2)
Comptes Rendus Chimie     Full-text available via subscription  
Comptes Rendus Physique     Full-text available via subscription   (Followers: 1)
Computational and Theoretical Chemistry     Hybrid Journal   (Followers: 9)
Computational Biology and Chemistry     Hybrid Journal   (Followers: 12)
Computational Chemistry     Open Access   (Followers: 2)
Computers & Chemical Engineering     Hybrid Journal   (Followers: 9)
Coordination Chemistry Reviews     Full-text available via subscription   (Followers: 2)
Copernican Letters     Open Access   (Followers: 1)
Critical Reviews in Biochemistry and Molecular Biology     Hybrid Journal   (Followers: 5)
Crystal Structure Theory and Applications     Open Access   (Followers: 3)
CrystEngComm     Full-text available via subscription   (Followers: 12)
Current Catalysis     Hybrid Journal   (Followers: 2)
Current Metabolomics     Hybrid Journal   (Followers: 5)
Current Opinion in Colloid & Interface Science     Hybrid Journal   (Followers: 9)
Current Research in Chemistry     Open Access   (Followers: 8)
Current Science     Open Access   (Followers: 58)
Dalton Transactions     Full-text available via subscription   (Followers: 22)
Detection     Open Access   (Followers: 2)
Developments in Geochemistry     Full-text available via subscription   (Followers: 2)
Diamond and Related Materials     Hybrid Journal   (Followers: 12)
Dislocations in Solids     Full-text available via subscription  
Doklady Chemistry     Hybrid Journal  
Drying Technology: An International Journal     Hybrid Journal   (Followers: 4)
Eclética Química     Open Access   (Followers: 1)
Ecological Chemistry and Engineering S     Open Access   (Followers: 4)
Ecotoxicology and Environmental Contamination     Open Access  
Educación Química     Open Access   (Followers: 1)
Education for Chemical Engineers     Hybrid Journal   (Followers: 5)
EJNMMI Radiopharmacy and Chemistry     Open Access  
Elements     Full-text available via subscription   (Followers: 2)
Environmental Chemistry     Hybrid Journal   (Followers: 8)
Environmental Chemistry Letters     Hybrid Journal   (Followers: 4)
Environmental Science & Technology Letters     Full-text available via subscription   (Followers: 5)
Environmental Science : Nano     Partially Free   (Followers: 1)
Environmental Toxicology & Chemistry     Hybrid Journal   (Followers: 17)

        1 2 3 | Last

Journal Cover Arabian Journal of Chemistry
  [SJR: 0.512]   [H-I: 20]   [6 followers]  Follow
    
  This is an Open Access Journal Open Access journal
   ISSN (Print) 1878-5352
   Published by Elsevier Homepage  [3044 journals]
  • Potentiometric and surface topography studies of new carbon-paste sensors
           for determination of thiamine in Egyptian multivitamin ampoules

    • Authors: Yousry M. Issa; Fekria M. Abou Attia; Omaima E. Sherif; Ahmed S. Abo Dena
      Pages: 751 - 760
      Abstract: Publication date: September 2017
      Source:Arabian Journal of Chemistry, Volume 10, Issue 6
      Author(s): Yousry M. Issa, Fekria M. Abou Attia, Omaima E. Sherif, Ahmed S. Abo Dena
      We report here for the first time two potentiometric carbon-paste sensors for determination of thiamine chloride hydrochloride in aqueous solutions. The proposed sensors use the ion-pair of thiamine with tetraphenylborate as an electro-active species and dibutyl phthalate (sensor I) or o-nitrophenyloctyl ether (sensor II) as solvent mediators. The effect of solvent mediator was studied using dibutyl phthalate, o-nitrophenyloctyl ether, ethylhexyl adipate, dioctyl phthalate, tricresyl phosphate and paraffin oil. The slopes of the calibration graphs are 29.49±0.24 and 29.60±0.15mV/decade for sensors (I) and (II), respectively. The sensors are able to detect down to 5.25×10−6 and 3.57×10−6 for (I) and (II), respectively. Both sensors show reasonable thermal stability and fast response time. The selectivity coefficients obtained from the matched potential method indicate high selectivity of the proposed sensors toward thiamine over commonly interfering cations. Sensor (I) has a lifetime of only 1–2days; however, sensor (II) remains usable for up to one month. Analytical applications to pure solutions and Egyptian multivitamin ampoules show excellent recovery values ranging from 97.92 to 103.72% and 97.21 to 102.19% for sensors (I) and (II), respectively. Moreover, the precision and reproducibility of the sensors are indicated from the low values of %RSD of five replicate measurements. In addition, the surface topography of the sensors was studied using scanning electron microscopy to investigate the effect of chemical modification on the surface structure.

      PubDate: 2017-09-06T14:51:18Z
      DOI: 10.1016/j.arabjc.2016.11.012
       
  • Synthesis, characterization, thermal and catalytic properties of a novel
           carbazole derived Azo ligand and its metal complexes

    • Authors: Selma Bal; Joseph Donald Connolly
      Pages: 761 - 768
      Abstract: Publication date: September 2017
      Source:Arabian Journal of Chemistry, Volume 10, Issue 6
      Author(s): Selma Bal, Joseph Donald Connolly
      This work explains the synthesis of a new azo-Schiff base compound, derived from condensation between N-ethylcarbazole-3-carbaldehyde and 1,3-diaminopropane, followed by azo coupling reaction with the diazonium salt of 2-amino-4-methyl phenol. The newly synthesized azo-Schiff base was further reacted with the acetate salts of Copper, Cobalt and Nickel to give three coordination compounds. All synthesized compounds have been characterized through spectral analysis. The coordination compounds have been examined for their thermal and catalytic features. Good and moderate yields were obtained for the oxidation of styrene and cyclohexene. Thermal features of the ligand and its complexes have been explained and the results obtained have supported the proposed structures.

      PubDate: 2017-09-06T14:51:18Z
      DOI: 10.1016/j.arabjc.2015.11.012
       
  • DFT analysis and bioactivity of 2-((E)-(4-methoxybenzylimino)methyl)phenol
           and its Ni(II) and Pd(II) complexes

    • Authors: Amalina Mohd Tajuddin; El Hassane Anouar; Kalavathy Ramasamy; Bohari M. Yamin; Abdulrahman I. Alharthi; Hadariah Bahron
      Pages: 769 - 780
      Abstract: Publication date: September 2017
      Source:Arabian Journal of Chemistry, Volume 10, Issue 6
      Author(s): Amalina Mohd Tajuddin, El Hassane Anouar, Kalavathy Ramasamy, Bohari M. Yamin, Abdulrahman I. Alharthi, Hadariah Bahron
      This paper reports the synthesis, characterisation and DFT analysis of an N,O bidentate Schiff base, ((E)-(4-methoxybenzylimino)methyl)phenol, (L1c) and its Ni(II) and Pd(II) complexes. The structures were elucidated via elemental analysis, UV–Visible, NMR, IR and single crystal X-ray diffraction. Complexation of L1c with Ni(II) and Pd(II) was observed to induce different degrees of bathochromic effect on n→π∗ and π→π∗ electronic transitions. A comparison of the experimental data of UV–Visible, NMR, IR and X-ray with those calculated using DFT and TD-DFT methods where five hybrid functionals were tested in gas, IEF-PCM and SS-PCM models was also carried out. The results show that the reproduction of maximum absorption bands n→π∗ and π→π∗ is strongly related to the tested hybrid functionals and solvatochromic effects. Relatively good concordance was obtained between experimental and calculated NMR chemical shifts, IR and X-ray parameters. A bioactivity evaluation against HCT116 and Escherichia coli displayed that the parent ligand L1c is a more superior anticancer and antibacterial agent than the positive controls of 5FU and gentamicin respectively. However, both complexes showed poor activity as anticancer agent and no activity observed against tested bacteria.

      PubDate: 2017-09-06T14:51:18Z
      DOI: 10.1016/j.arabjc.2016.11.005
       
  • Multi-wavelength thermal-lens spectrometry for high-accuracy measurements
           of absorptivities and quantum yields of photodegradation of a
           hemoprotein–lipid complex

    • Authors: Kseniya Tishchenko; Marina Muratova; Dmitry Volkov; Vera Filichkina; Dmitry Nedosekin; Vladimir Zharov; Mikhail Proskurnin
      Pages: 781 - 791
      Abstract: Publication date: September 2017
      Source:Arabian Journal of Chemistry, Volume 10, Issue 6
      Author(s): Kseniya Tishchenko, Marina Muratova, Dmitry Volkov, Vera Filichkina, Dmitry Nedosekin, Vladimir Zharov, Mikhail Proskurnin
      Accurate measurements of absorptivities and quantum yields of biochemical species under various conditions are an important task of applied photonics and analytical chemistry. In this work, we provide a comparison of the capabilities of thermal-lens spectrometry to measure these parameters of various samples. Measurements of relevant model substances, biologically active substituted 2-thiohydantoins and their complexes of copper(I,II) and heme proteins (forms of hemoglobin and cytochrome c), showed negligible differences in apparent molar absorptivities for thermal-lens spectrometry and optical-absorption (spectrophotometric) data. The values for tabletop and microscale thermal-lens measurements under batch conditions differ insignificantly. The precision of measurements of molar absorptivities by thermal-lens spectrometry is no less than in the case of spectrophotometry or the precision is even higher in the cases of low absorptivities. For cardiolipin–cytochrome c-NO complex, the difference between absorptivity values calculated from thermal-lens data and acquired by spectrophotometry is significant due to complex photodegradation. The quantum yield of its photolysis reaction calculated from optical absorption and thermal-lens data altogether at two wavelengths for 0.4–360s of the reaction, 0.46±0.04, was estimated.

      PubDate: 2017-09-06T14:51:18Z
      DOI: 10.1016/j.arabjc.2016.01.009
       
  • High-performance liquid chromatography method development for the quality
           control of Ginkgonis Semen

    • Authors: Vu Ngoc Han Le; Wonjae Lee; Young Ho Kim; Gyu Han Chae; Young-Won Chin; Kyung Tae Kim; Jong Seong Kang
      Pages: 792 - 800
      Abstract: Publication date: September 2017
      Source:Arabian Journal of Chemistry, Volume 10, Issue 6
      Author(s): Vu Ngoc Han Le, Wonjae Lee, Young Ho Kim, Gyu Han Chae, Young-Won Chin, Kyung Tae Kim, Jong Seong Kang
      Ginkgonis Semen (GS) is the seed of Ginkgo biloba Linné and a valuable material for herbal medicines and functional foods in China, Japan and Korea. The main bio-compounds of GS are GA, GB and GC like the leaves. There are many studies for the analysis of ginkgolides in the leaves or leaves extract of G. biloba because the leaves extract is a valuable material in pharmaceutical industries. However, there is no efficient analytical method for the quality control of GS based on the quantitation of ginkgolides because of matrix effect induced by different chemical composition. So, there are no content criteria of GS in Pharmacopoeia of Korea, Japan and China until now. This study aimed to develop HPLC method using ginkgolides based on the quantitation of GA, GB and GC for the quality control of GS with the optimization of sample preparation to enhance the analytical sensitivity and reproducibility. At first, defatting process using petroleum ether and liquid–liquid extraction were applied for sample preparation to remove matrix effect. The HPLC-ELSD method was developed with the mobile phase of a 0.5% aqueous acetic acid and methanol–acetonitrile solution (1:1 ratio) under gradient conditions. GA, GB and GC contents in GS were different between Korea and China. The mean quantity of Korean samples was 4.85±2.33μg/g GA, 48.38±5.10μg/g GB, and 37.83±7.64μg/g GC. Those contents of Chinese samples were higher than Korean samples as 9.39±2.51μg/g GA, 123.59±26.24μg/g GB and 53.39±4.97μg/g GC. It indicated that the discrimination of GS between Korea and China could be achieved by marker compound contents. Furthermore, the geographical discrimination of GS between Korea and China was confirmed by PCA using the quantitative data of marker compounds. By statistical analysis, the calculated content criteria of GS by regression method were 2.35μg/g of GA, 29.20μg/g of GB, and 27.75μg/g of GC, based on dry weight. Thus, our HPLC method shows potential toward the development of a universal quality control methodology to quantify GS quality and origin.

      PubDate: 2017-09-06T14:51:18Z
      DOI: 10.1016/j.arabjc.2016.10.007
       
  • QSAR study of the non-peptidic inhibitors of procollagen C-proteinase
           based on Multiple linear regression, principle component regression, and
           partial least squares

    • Authors: Ardeshir Khazaei; Negin Sarmasti; Jaber Yousefi Seyf; Zahra Rostami; Mohammad Ali Zolfigol
      Pages: 801 - 810
      Abstract: Publication date: September 2017
      Source:Arabian Journal of Chemistry, Volume 10, Issue 6
      Author(s): Ardeshir Khazaei, Negin Sarmasti, Jaber Yousefi Seyf, Zahra Rostami, Mohammad Ali Zolfigol
      The quantitative structure–activity relationship (QSAR) analyses were carried out in a series of novel sulfonamide derivatives as the procollagen C-proteinase inhibitors for treatment of fibrotic conditions. Sphere exclusion method was used to classify data set into categories of train and test set at different radii ranging from 0.9 to 0.5. Multiple linear regression (MLR), principal component regression (PCR) and partial least squares (PLS) were used as the regression methods and stepwise, Genetic algorithm (GA), and simulated annealing (SA) were used as the feature selection methods. Three of the statistically best significant models were chosen from the results for discussion. Model 1 was obtained by MLR–SA methodology at a radius of 1.6. This model with a coefficient of determination (r 2)=0.71 can well predict the real inhibitor activities. Cross-validated q 2 of this model, 0.64, indicates good internal predictive power of the model. External validation of the model (pred_r 2 =0.85) showed that the model can well predict activity of novel PCP inhibitors. The model 2 which developed using PLS–SW explains 72% (r 2 =0.72) of the total variance in the training set as well as it has internal (q 2) and external (pred_r 2) predictive ability of ∼67% and ∼71% respectively. The last developed model by PCR–SA has a correlation coefficient (r 2) of 0.68 which can explains 68% of the variance in the observed activity values. In this case internal and external validations are 0.61 and 0.75, respectively. Alignment Independent (AI) and atomic valence connectivity index (chiv) have the greatest effect on the biological activities. Developed models can be useful in designing and synthesis of effective and optimized novel PCP inhibitors which can be used for treatment of fibrotic conditions.

      PubDate: 2017-09-06T14:51:18Z
      DOI: 10.1016/j.arabjc.2015.02.016
       
  • Facile synthesis of Ni-decorated multi-layers graphene sheets as effective
           anode for direct urea fuel cells

    • Authors: Ahmed Yousef; Mohamed H. El-Newehy; Salem S. Al-Deyab; Nasser A.M. Barakat
      Pages: 811 - 822
      Abstract: Publication date: September 2017
      Source:Arabian Journal of Chemistry, Volume 10, Issue 6
      Author(s): Ahmed Yousef, Mohamed H. El-Newehy, Salem S. Al-Deyab, Nasser A.M. Barakat
      A large amount of urea-containing wastewater is produced as a by-product in the fertilizer industry, requiring costly and complicated treatment strategies. Considering that urea can be exploited as fuel, this wastewater can be treated and simultaneously exploited as a renewable energy source in a direct urea fuel cell. In this study, multi-layers graphene/nickel nanocomposites were prepared by a one-step green method for use as an anode in the direct urea fuel cell. Typically, commercial sugar was mixed with nickel(II) acetate tetrahydrate in distilled water and then calcined at 800°C for 1h. Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and energy dispersive spectroscopy (EDS) were employed to characterize the final product. The results confirmed the formation of multi-layers graphene sheets decorated by nickel nanoparticles. To investigate the influence of metal nanoparticles content, samples were prepared using different amounts of the metal precursor; nickel acetate content was changed from 0 to 5wt.%. Investigation of the electrochemical characterizations indicated that the sample prepared using the original solution with 3wt.% nickel acetate had the best current density, 81.65mA/cm2 in a 0.33M urea solution (in 1M KOH) at an applied voltage 0.9V vs Ag/AgCl. In a passive direct urea fuel cell based on the optimal composition, the observed maximum power density was 4.06×10−3 mW/cm2 with an open circuit voltage of 0.197V at room temperature in an actual electric circuit. Overall, this study introduces a cheap and beneficial methodology to prepare effective anode materials for direct urea fuel cells.

      PubDate: 2017-09-06T14:51:18Z
      DOI: 10.1016/j.arabjc.2016.12.021
       
  • Comparative spectroscopic and electrochemical study of N-1 or
           N-2-alkylated 4-nitro and 7-nitroindazoles

    • Authors: Gabriele Micheletti; Assoman Kouakou; Carla Boga; Paola Franchi; Matteo Calvaresi; Lorella Guadagnini; Marco Lucarini; El Mostapha Rakib; Domenico Spinelli; Domenica Tonelli; Issam Forsal
      Pages: 823 - 836
      Abstract: Publication date: September 2017
      Source:Arabian Journal of Chemistry, Volume 10, Issue 6
      Author(s): Gabriele Micheletti, Assoman Kouakou, Carla Boga, Paola Franchi, Matteo Calvaresi, Lorella Guadagnini, Marco Lucarini, El Mostapha Rakib, Domenico Spinelli, Domenica Tonelli, Issam Forsal
      Our research groups are by long time involved in the study of the reactivity and the pharmacological activity of nitrogen-containing heterocyclic compounds: in this line we have now examined the behaviour of some substituted 4- and 7-nitroindazoles. Considering the fact that nitroreduction processes are often essential steps for the biological activity of nitro compounds and remembering that some nitroindazoles show interesting biological activities, we have collected nuclear magnetic resonance, electron spin resonance, and cyclic voltammetry data and carried out density functional theory computations on the above compounds thus obtaining an accurate picture of electronic distribution and reduction processes of the examined substrates as a function of their chemical structure. Looking also to our previous results obtained examining the behaviour of 5- and 6-nitroindazoles, we have confirmed the different general behaviour of 1- and 2-alkyl substituted nitroindazoles strictly related to the known different electronic distribution in these two classes of compounds. Interestingly, cyclic voltammetry data have confirmed the ability of N-1H nitroindazoles to give rise to the formation of dimers, already observed by us studying 5- and 6-nitroindazoles.

      PubDate: 2017-09-06T14:51:18Z
      DOI: 10.1016/j.arabjc.2016.05.005
       
  • Furfuryl alcohol functionalized graphene for sorption of radionuclides

    • Authors: Xing Chen; Xiaoli Wang; Shaowei Wang; Junsheng Qi; Kun Xie; Xia Liu; Jiaxing Li
      Pages: 837 - 844
      Abstract: Publication date: September 2017
      Source:Arabian Journal of Chemistry, Volume 10, Issue 6
      Author(s): Xing Chen, Xiaoli Wang, Shaowei Wang, Junsheng Qi, Kun Xie, Xia Liu, Jiaxing Li
      In this study, graphene was functionalized with furfuryl alcohol (FA) through the Diels–Alder reaction. The as-prepared FA functionalized graphene (FAG) was characterized by XRD, Raman, TEM, AFM, FT-IR and TG. The sorption performance of the obtained FAG toward radionuclides was evaluated. The maximum sorption capacities from the Langmuir model were calculated to be 1.178, 1.947, 1.431 and 1.608mmolg−1 for U(VI), Eu(III), Sr(II), and Co(II), respectively, at T =303K and pH=3.0, indicating the hierarchical binding affinity of the FAG surface toward the radionuclides in the order Eu(III)>Co(II)>Sr(II)>U(VI). Based on the experimental results presented in this study, it is clear that FAG can be potentially used as a promising candidate for the sorption of radionuclides.

      PubDate: 2017-09-06T14:51:18Z
      DOI: 10.1016/j.arabjc.2016.06.009
       
  • Diethylenetriamine/diamines/copper (II) complexes [Cu(dien)(NN)]Br2:
           Synthesis, solvatochromism, thermal, electrochemistry, single crystal,
           Hirshfeld surface analysis and antibacterial activity

    • Authors: Fatima Abu Saleemh; Sharif Musameh; Ashraf Sawafta; Paula Brandao; Carlos Jose Tavares; Stanislav Ferdov; Assem Barakat; Anas Al Ali; Mousa Al-Noaimi; Ismail Warad
      Pages: 845 - 854
      Abstract: Publication date: September 2017
      Source:Arabian Journal of Chemistry, Volume 10, Issue 6
      Author(s): Fatima Abu Saleemh, Sharif Musameh, Ashraf Sawafta, Paula Brandao, Carlos Jose Tavares, Stanislav Ferdov, Assem Barakat, Anas Al Ali, Mousa Al-Noaimi, Ismail Warad
      Two dicationic water soluble mixed triamine/diamine copper (II) complexes, of general formula [Cu(dien)NN]Br2 (1–2) [dien=diethelenetriamine and NN is en =ethylenediamine or Me4en =N,N′,N,N′-tetramethylethylenediamine] were prepared under ultrasonic mode with a relatively high yield. These complexes were characterized by elemental microanalysis, UV visible IR spectroscopy, and thermal and electrochemical techniques. In addition, complex 2 structure was solved by X-ray single crystal and Hirshfeld surface analysis. The complex exhibits a distorted square pyramidal coordination environment around Cu(II) centre. The solvatochromism of the desired complexes was investigated in water and other suitable organic solvents. The results show that the Guttmann’s DN parameter values of the solvents have mainly contributed to the shift of the d–d absorption band towards the linear increase in the wavelength of the absorption maxima of the complexes. The complex 1 showed higher antibacterial activity against the studied microorganisms compared to complex 2. Both complexes revealed promising antibacterial activities.

      PubDate: 2017-09-06T14:51:18Z
      DOI: 10.1016/j.arabjc.2016.10.008
       
  • Investigation of intercalation of diphenhydramine into the interlayer of
           smectite by XRD, FTIR, TG-DTG analyses and molecular simulation

    • Authors: Guocheng Lv; Po-Hsiang Chang; Xuebing Xing; Wei-Teh Jiang; Jiin-Shuh Jean; Zhaohui Li
      Pages: 855 - 861
      Abstract: Publication date: September 2017
      Source:Arabian Journal of Chemistry, Volume 10, Issue 6
      Author(s): Guocheng Lv, Po-Hsiang Chang, Xuebing Xing, Wei-Teh Jiang, Jiin-Shuh Jean, Zhaohui Li
      Diphenhydramine (DPH) is one of the pharmaceuticals commonly found in the effluent stream after wastewater treatment, and the cause of its environmental persistence needs to be addressed urgently. Smectite minerals are common soil components with large surface area, expandable interlayer, and high cation exchange capacity (CEC), thus are capable of adsorbing or intercalating inorganic or organic cations on the surface or in the interlayer. In this study the intercalation of DPH in the interlayer of a Ca-smectite was characterized by X-ray diffraction, infra-red, and thermogravimetric analyses supported by molecular dynamic simulation. At the low (0.2–0.3 CEC) and high (0.6–0.7 CEC) adsorption levels, the intercalated DPH might take a horizontal monolayer or a bilayer configuration, resulting in a d001 expansion to 15 or 17Å, respectively. As the amount of DPH intercalation increased, a gradual, yet systematic, dehydration due to removal of hydrated inorganic cation Ca2+ from the interlayer was observed. In addition, the intercalated DPH had a slightly higher thermal stability due to the shield effect of the host mineral smectite against heat. The uptake of DPH by the smectite was attributed to both electrostatic interactions between the negatively charged mineral surfaces and the positively charged tertiary amine and cation exchange interactions between DPH+ and hydrated Ca2+. Thus, smectite minerals could serve as a sink to remove dissolved DPH from water on the one hand, and as a carrier to transport intercalated DPH in the environment on the other hand.

      PubDate: 2017-09-06T14:51:18Z
      DOI: 10.1016/j.arabjc.2015.04.016
       
  • Green synthesized silver nanoparticles destroy multidrug resistant
           bacteria via reactive oxygen species mediated membrane damage

    • Authors: Balaram Das; Sandeep Kumar Dash; Debasish Mandal; Totan Ghosh; Sourav Chattopadhyay; Satyajit Tripathy; Sabyasachi Das; Sankar Kumar Dey; Debasis Das; Somenath Roy
      Pages: 862 - 876
      Abstract: Publication date: September 2017
      Source:Arabian Journal of Chemistry, Volume 10, Issue 6
      Author(s): Balaram Das, Sandeep Kumar Dash, Debasish Mandal, Totan Ghosh, Sourav Chattopadhyay, Satyajit Tripathy, Sabyasachi Das, Sankar Kumar Dey, Debasis Das, Somenath Roy
      The growing need of antimicrobial agent for novel therapies against multi-drug resistant bacteria has drawn researchers to green nanotechnology. Especially, eco-friendly biosynthesis of silver nanoparticles (Ag NPs) has shown its interesting impact against bacterial infection in laboratory research. In this study, a simple method was developed to form Ag NPs at room temperature, bio-reduction of silver ions from silver nitrate salt by leaf extract from Ocimum gratissimum. The Ag NPs appear to be capped with plant proteins, but are otherwise highly crystalline and pure. The Ag NPs have a zeta potential of −15mV, a hydrodynamic diameter of 31nm with polydispersity index of 0.65, and dry sizes of 18±3nm and 16±2nm, based on scanning and transmission electron microscopy respectively. The minimum inhibitory concentration (MIC) of the Ag NPs against a multi-drug resistant Escherichia coli was 4μg/mL and the minimum bactericidal concentration (MBC) was 8μg/mL, while the MIC and MBC against a resistant strain of Staphylococcus aureus were slightly higher at 8μg/mL and 16μg/mL respectively. Further, the Ag NPs inhibited biofilm formation by both Escherichia coli and S. aureus at concentrations similar to the MIC for each strain. Treatment of E. coli and S. aureus with Ag NPs resulted in damage to the surface of the cells and the production of reactive oxygen species. Both mechanisms likely contribute to bacterial cell death. In summary, this new method appears promising for green biosynthesis of pure Ag NPs with potent antimicrobial activity.

      PubDate: 2017-09-06T14:51:18Z
      DOI: 10.1016/j.arabjc.2015.08.008
       
  • Flower-shaped gold nanoparticles: Preparation, characterization, and
           electrocatalytic application

    • Authors: Islam M. Al-Akraa; Ahmad M. Mohammad; Mohamed S. El-Deab; Bahgat E. El-Anadouli
      Pages: 877 - 884
      Abstract: Publication date: September 2017
      Source:Arabian Journal of Chemistry, Volume 10, Issue 6
      Author(s): Islam M. Al-Akraa, Ahmad M. Mohammad, Mohamed S. El-Deab, Bahgat E. El-Anadouli
      The modification of a glassy carbon electrode with gold nanoparticles was pursued, characterized, and examined for electrocatalytic applications. The fabrication process of this electrode involved assembling the gold nanoparticles atop of amino group grafted glassy carbon electrode. The scanning electron microscopy indicated the deposition of gold nanoparticles in flower-shaped nanostructures with an average particle size of ca. 150nm. Interestingly, the electrode exhibited outstanding enhancement in the electrocatalytic activity toward the oxygen evolution reaction, which reflected from the large negative shift (ca. 0.8V) in its onset potential, in comparison with that observed at the bulk unmodified glassy carbon and gold electrodes. Alternatively, the Tafel plot of the modified electrode revealed a significant increase (∼one order of magnitude) in the apparent exchange current density of the oxygen evolution reaction upon the modification, which infers a faster charge transfer. Kinetically, gold nanoparticles are believed to facilitate a favorable adsorption of OH− (fundamental step in oxygen evolution reaction), which allows the charge transfer at reasonably lower anodic polarizations.

      PubDate: 2017-09-06T14:51:18Z
      DOI: 10.1016/j.arabjc.2015.05.004
       
  • α-Titanium phosphate intercalated with propylamine: An alternative
           pathway for efficient europium(III) uptake into layered tetravalent metal
           phosphates

    • Authors: Jorge García-Glez; Camino Trobajo; Sergei A. Khainakov; Zakariae Amghouz
      Pages: 885 - 894
      Abstract: Publication date: September 2017
      Source:Arabian Journal of Chemistry, Volume 10, Issue 6
      Author(s): Jorge García-Glez, Camino Trobajo, Sergei A. Khainakov, Zakariae Amghouz
      α-Ti(HPO4)2·H2O (α-TiP) and its propylamine intercalation product, Ti(HPO4)2·2C3H7NH2·H2O (α-TiPPr), have been synthesized and characterized. Later, their sorption capacity for europium(III) was investigated, and this purpose was accomplished by treating α-TiP and α-TiPPr with europium(III) nitrate solutions at different concentrations until the equilibrium is reached. All samples were characterized, among others, by powder X-ray diffraction (PXRD), scanning and transmission electron microscopies (SEM, TEM, STEM-EDX, SAED), thermogravimetric analysis (TGA), and photoluminescence (PL) measurements. The results show that the Eu3+ uptake is limited to surface when α-TiP is used as sorbent. Nevertheless, the Eu-retention is considerably enhanced with α-TiPPr as a consequence of an ion-exchange process into the interlayer space of the layered titanium phosphate (involving propylammonium cations, C3H7NH3 +, and hexahydrate europium(III) species, [Eu(H2O)6]3+), and the crystal structure of a hypothetical final product, α-[Eu(H2O)6]2/3Ti(PO4)2·[(H2O)6]1/3, has been proposed by using DFT calculations.

      PubDate: 2017-09-06T14:51:18Z
      DOI: 10.1016/j.arabjc.2016.07.013
       
  • The chemical composition on fingerprint of Glandora diffusa and its
           biological properties

    • Authors: Fátima Fernandes; Paula B. Andrade; Federico Ferreres; Angel Gil-Izquierdo; Isabel Sousa-Pinto; Patrícia Valentão
      Pages: 583 - 595
      Abstract: Publication date: July 2017
      Source:Arabian Journal of Chemistry, Volume 10, Issue 5
      Author(s): Fátima Fernandes, Paula B. Andrade, Federico Ferreres, Angel Gil-Izquierdo, Isabel Sousa-Pinto, Patrícia Valentão
      Glandora diffusa (Lag.) D.C. Thomas is a medicinal species widely consumed as herbal tea. Despite being commercialized by several herbs distributors, the genuineness of the marketed product is unknown. Among secondary metabolites with proven taxonomic interest, the phenolics profile was herein used as “fingerprint” of three commercial G. diffusa samples. Furthermore, the knowledge on the composition of this species was extended and its amino acids, fatty acids, sterols and triterpenes profiles were studied for the first time. The phenolics profile was characterized by HPLC-DAD. All other metabolites were determined by GC–MS. Despite similar qualitative profiles, significant quantitative differences were observed among the three samples. Their potential as antioxidant and anti-Alzheimer and cytotoxicity was evaluated and relationship between chemical composition and activities was considered. Ethanolic extracts showed a potent dose-dependent response against DPPH , a mild inhibitory effect on both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) and to be toxic to both human colorectal (Caco-2) and gastric adenocarcinoma (AGS) cells only for high concentrations. This work covers interdisciplinary aspects in the pharmaceutical and biomedical sciences, by focusing on metabolic profiling and quality assurance of a medicinal species used in folk medicine. The results improve the knowledge on G. diffusa and encourage its use, not only as herbal tea, as it is traditionally consumed, but also in pharmaceutical preparations, ethanol being a cheap and feasible solvent to recover its bioactive components.

      PubDate: 2017-06-20T05:49:34Z
      DOI: 10.1016/j.arabjc.2015.01.012
       
  • WO3 Decorated Carbon Nanotube Supported PtSn Nanoparticles with Enhanced
           Activity towards Electrochemical Oxidation of Ethylene Glycol in Direct
           Alcohol Fuel Cells

    • Authors: Krzysztof Miecznikowski
      Abstract: Publication date: Available online 14 September 2017
      Source:Arabian Journal of Chemistry
      Author(s): Krzysztof Miecznikowski
      This paper describes the concept of the utilization of metal oxide (WO3) modified multi-walled carbon nanotubes (MWCNT) for supporting and activating PtSn nanoparticles (PtSn/WO3-MWCNT and PtSn/MWCNT) for ethylene glycol oxidation. The resulting nanocomposite was developed and characterized using electrochemical and microscopic (TEM, SEM-EDS) techniques, as well as XRD analysis. The electrocatalytic currents measured under voltammetric and chronoamperometric conditions were greater than those found with the commercially available Vulcan-supported Pt3Sn nanoparticles, which were used as reference catalysts. In situ FTIR spectroscopy was used to detect the formation of oxidation intermediates or products during the ethylene glycol oxidation. Combining the transition metal oxide species with Pt-based nanoparticles can generate –OH groups at low potentials. These groups participate in the oxidation of passivating CO adsorbates on the Pt surface, and can also potentially break C-H bonds. Further, the effectiveness of synthesized catalyst has been assessed through testing both catalysts in the single fuel cell. A single fuel cell with a PtSn/WO3-MWCNT anode gave a better performance than one with a pristine PtSn/Vulcan anode, with a current density of around 79.8 mA cm-2 and an output power density of 20.5 mW cm-2.

      PubDate: 2017-09-18T17:13:36Z
      DOI: 10.1016/j.arabjc.2017.09.005
       
  • Enhanced photocatalytic activity of ZnO nanoparticles by surface
           modification with KF using thermal shock method

    • Authors: Tien Khoa Le; Thi Minh Tram Nguyen; Huu Thinh Pham Nguyen; Thi Kieu Loan Nguyen; Torben Lund; Huu Khanh Hung Nguyen; Thi Kieu Xuan Huynh
      Abstract: Publication date: Available online 14 September 2017
      Source:Arabian Journal of Chemistry
      Author(s): Tien Khoa Le, Thi Minh Tram Nguyen, Huu Thinh Pham Nguyen, Thi Kieu Loan Nguyen, Torben Lund, Huu Khanh Hung Nguyen, Thi Kieu Xuan Huynh
      ZnO nanoparticles were modified with KF using thermal shock method at various temperatures in order to improve the photocatalytic activity of ZnO under both UVA and visible light irradiation. The influences of KF-modification on the crystal structure, morphology, UV-visible absorption, specific surface area as well as surface structure of ZnO were respectively characterized by XRD, FE-SEM, UV-Visible diffuse reflectance, N2 adsorption and XPS spectroscopy. The photocatalytic activity was evaluated via the degradation of methylene blue under UVA irradiation. According to the results, the thermal shock process with KF did not modify the structure, the particle size and the optical properties of ZnO nanoparticles but successfully increase their UVA and visible light induced photocatalytic activity. This enhancement of activity may be attributed to the increase of surface hydroxyl groups and zinc vacancies of modified ZnO samples.

      PubDate: 2017-09-18T17:13:36Z
      DOI: 10.1016/j.arabjc.2017.09.006
       
  • Effect of temperature on the size of biosynthesized silver nanoparticle:
           deep insight into microscopic kinetics analysis

    • Authors: Hongyu Liu; Huan Zhang; Jie Wang; Junfu Wei
      Abstract: Publication date: Available online 14 September 2017
      Source:Arabian Journal of Chemistry
      Author(s): Hongyu Liu, Huan Zhang, Jie Wang, Junfu Wei
      Lacking of microscopic insight into quantitative nucleation and growth kinetics analysis, the effect of temperature on particle size in wet chemical synthesis of metal nanoparticles is still not fully understood. Firstly, we investigated the influence of temperature on the nucleation kinetics constant k1 and growth kinetics constant k2. Based on the microscopic quantitative kinetics analysis, the influence of temperature on size of nanoparticles was discussed and concluded in detail. In order to test and verify the conclusions, synthesis of AgNPs under sufficient and insufficient Ag+ precursors respectively was carried out. Temperature exhibits different effect on the size of nanoparticles under sufficient and insufficient Ag+ precursors due to its impressively different influence on the nucleation kinetics constant k1 and growth kinetics constant k2. It is the first time to discuss the effect of temperature on size of nanoparticles in detail based on the microscopic quantitative kinetics analysis. Our work provides useful deep insight into microscopic kinetics analysis of the effect of temperature on size distribution of AgNPs.

      PubDate: 2017-09-18T17:13:36Z
      DOI: 10.1016/j.arabjc.2017.09.004
       
  • Synthesis and special characterization through X-ray analysis of
           1,8-dioxooctahydroxanthenes

    • Authors: Milene Lopes da Silva; Róbson Ricardo Teixeira; Lucas de Azevedo Santos; Felipe Terra Martins; Teodorico Castro Ramalho
      Abstract: Publication date: Available online 9 September 2017
      Source:Arabian Journal of Chemistry
      Author(s): Milene Lopes da Silva, Róbson Ricardo Teixeira, Lucas de Azevedo Santos, Felipe Terra Martins, Teodorico Castro Ramalho
      Pyran moiety containing heterocyclic compounds have the capability for binding to either side to cyclohex-2-enone rings and to form xanthene derivatives (1,8-dioxooctahydroxanthenes also known as xanthenodiones). These xanthene derivatives display a wide range of biological activities and find applications in laser technologies and photodynamic therapy. This paper describes the preparation, X-ray structural analysis, and theoretical investigation of a series of 1,8-dioxooctahydroxanthenes. The compounds were synthesized via Knoevenagel condensation between different aldehydes and β-diketones. The reactions were performed free of solvents and the 1,8-dioxooctahydroxanthenes were obtained in good yields (70%−92%). All the compounds were fully characterized by NMR and IR spectroscopy as well as mass spectrometry. Among the synthesized compounds, seven had their crystal structures elucidated for the first time. In all the new crystal structures, the three fused rings did form an almost completely planar xanthenodione core, except for the side rings that adopt half-chair conformation with both carbons at the flaps oriented toward to the aromatic substituent, or with one of the two carbons pointing opposite to the substituent. Another conformational difference among the new compounds investigated by X-ray diffraction resides in the rotation around the bond axis connecting the xanthenodione core to its aromatic substituent. It was found that different bent levels resulted from weak intermolecular contact patterns. In addition, theoretical calculations for single molecule and dimmers have provided insights into the balance between intramolecular and intermolecular forces driving both conformational features.

      PubDate: 2017-09-12T16:04:37Z
      DOI: 10.1016/j.arabjc.2017.09.001
       
  • Inside Front Cover - Editorial Board

    • Abstract: Publication date: September 2017
      Source:Arabian Journal of Chemistry, Volume 10, Issue 6


      PubDate: 2017-09-06T14:51:18Z
       
  • Stereoselectivity of the Captodative Alkenes 1-Acetylvinyl
           Arenecarboxylates in Diels-Alder Reactions with Cyclic Dienes and
           Stereospecific Rearrangement of their Bicyclo[2.2.n] α-Ketol Adducts

    • Authors: Raúl Aguilar; Blanca M. Santoyo; Daniel Zárate-Zárate; Miguel A. Vázquez; Rosa M. Padilla; Hugo A. Jiménez-Vázquez; Joaquín Tamariz
      Abstract: Publication date: Available online 1 September 2017
      Source:Arabian Journal of Chemistry
      Author(s): Raúl Aguilar, Blanca M. Santoyo, Daniel Zárate-Zárate, Miguel A. Vázquez, Rosa M. Padilla, Hugo A. Jiménez-Vázquez, Joaquín Tamariz
      Captodative alkene 1-acetylvinyl p-nitrobenzenecarboxylate 1a was evaluated for its reactivity and stereoselectivity with cyclohexadiene (10) in Diels-Alder reactions, showing exclusive endo preference. The two hydrolyzed products of the endo and the exo adducts obtained from the Diels-Alder cycloaddition between 1a and cyclopentadiene (7) were 8b and 9b. When treated with mCPBA, a ring expansion took place to stereospecifically yield the novel 3-oxatricyclo[3.3.1.02,4]nonanone acyloins 15 and 16, respectively. In the case of the α-ketol bicyclo[2.2.2]octanes 11b and 12b, the epoxidation/Baeyer-Villiger cascade process was preferred, resulting in the syn ketoepoxide 19b from each isomer. A synthetic application of this kind of transformation was carried out by reacting ketols 8b and 9b with an excess of mCPBA through a five-step cascade process to yield the bicyclic lactone 27 as a potential precursor of racemic β-carbaxylose.
      Graphical abstract image

      PubDate: 2017-09-06T14:51:18Z
      DOI: 10.1016/j.arabjc.2017.08.008
       
  • Assessment of conventional and microwave heating effects on the variation
           of the bioactive compounds of Chétoui VOO using HPLC-DAD-ESI-TOF-MS

    • Authors: Imen Oueslati; Amani Taamalli; Anis Loubiri; David Arráez-Román; Antonio Segura-Carretero; Mokhtar Zarrouk
      Abstract: Publication date: Available online 1 September 2017
      Source:Arabian Journal of Chemistry
      Author(s): Imen Oueslati, Amani Taamalli, Anis Loubiri, David Arráez-Román, Antonio Segura-Carretero, Mokhtar Zarrouk
      The goal of this work was to monitor the hydrophilic profile of the virgin olive oil (VOO) of the second main Tunisian variety, “Chétoui”, in order to achieve a better understanding of the behavior of the bioactive phenolic compounds during 0, 2, 5, 10, and 15 min of microwave heating at medium power 800 W, and 0, 2.5, and 5 h of conventional heating at 180°C. The extent of the oxidative and hydrolytic degradation of the different phenolic subclasses was evaluated using high-performance liquid chromatography (HPLC) coupled to electrospray time-of-flight mass spectrometry (TOF-MS) method. During heating process, the most represented component in Chétoui VOO was found to be isomer 1 and 2 of deacetoxy oleuropein aglycone, and hydroxy decarboxy oleuropein aglycon. These compounds may be considered as direct markers for the degree of transformation of secoiridoids during heating process. Among the studied phenolic compounds, hydroxytyrosol, tyrosol, luteolin and apigenin displayed the highest heating resistance in the whole time range of microwave and conventional applications. However, the main secoiridoids quantified in the fresh VOO, isomer 2 of oleuropein aglycone, and ligstroside aglycone, decreased in concentration with the thermal treatment and this decrease was drastic under conventional heating.

      PubDate: 2017-09-06T14:51:18Z
      DOI: 10.1016/j.arabjc.2017.08.011
       
  • Bioinspired synthesis of pure massicot phase lead oxide nanoparticles and
           assessment of their biocompatibility, cytotoxicity and in-vitro biological
           properties

    • Authors: Ali Talha Khalil; Muhammad Ovais; Ikram Ullah; Muhammad Ali; Sohail Ahmad Jan; Zabta Khan Shinwari; Malik Maaza
      Abstract: Publication date: Available online 1 September 2017
      Source:Arabian Journal of Chemistry
      Author(s): Ali Talha Khalil, Muhammad Ovais, Ikram Ullah, Muhammad Ali, Sohail Ahmad Jan, Zabta Khan Shinwari, Malik Maaza
      Green and ecofriendly route for biosynthesis of lead oxide nanoparticles has been successfully demonstrated using aqueous leaf extracts of Sageretia thea (Osbeck.). Biosynthesized PbO (∼ 27 nm) nanoparticles were extensively characterized using XRD, FTIR, Raman, EDS etc. Morphology was studied through HR-TEM/SEM. As synthesized nanoparticles were investigated for their iv-vitro biological properties. Antibacterial activities revealed enhancement upon modulation by UV in a concentration dependent manner. Pseudomonas aeruginosa was found to be the most resistant strain (MIC = 250 µg/mL and MICuv = 31.25 µg/ml). MTT cytotoxicity on leishmania promastigotes and amastigotes revealed significant inhibition as indicated by their IC50 values of 14.7 µg/mL and 11.95 µg/m respectively. Cytotoxicity was also confirmed using brine shrimp lethality (IC50 = 27.7 µg/mL). Bio-compatibility evaluation indicated cytotoxicity to freshly isolated human macrophages (IC50 = 57.1 µg/mL). Insignificant alpha-amylase inhibition and moderate protein kinase inhibition was revealed. Antioxidant activities indicated free radical scavenging activity (58 ± 2.45) at 200 µg/mL. Moderate total reducing power and total antioxidant activity was also indicated. Overall, we conclude lead oxide as a potential candidate for biological applications, however further studies are recommended on their in-vitro and in-vivo cytotoxicity.
      Graphical abstract image

      PubDate: 2017-09-06T14:51:18Z
      DOI: 10.1016/j.arabjc.2017.08.009
       
  • Spectroscopic investigation and magnetic properties of Na2Pb1-xCuxP2O7
           glasses

    • Authors: Abadi Aride; Benkhouja Haddad Taibi
      Abstract: Publication date: Available online 1 September 2017
      Source:Arabian Journal of Chemistry
      Author(s): S. Abadi, J. Aride, K. Benkhouja, M. Haddad, M. Taibi
      Phosphate glasses have several technological interests due to their specific physical properties such as high thermal expansion coefficient, high refractive indice and low melting temperature, that make them suitable for use as conductors, ionic conductors, semiconductors and biomedical materials. The phosphate glasses, in particular the pyrophosphate forms, are not widely studied. In this work we have elaborated the Na2Pb1-xCuxP2O7 glasses, with a large range of composition (0≤x≤1), by conventional melting method. Thermal parameters of the glasses were determined using the differential scanning calorimetry. The structure of the glasses was investigated by IR spectroscopy. The local environment of paramagnetic ions Cu2+ was analyzed by EPR and magnetic measurements. It was showed that the network structure of the glasses was drastically influenced by the copper content.

      PubDate: 2017-09-06T14:51:18Z
       
  • A detailed experimental and computational study of monocarbohydrazones

    • Authors: Aleksandra R. Božić; Nenad R. Filipović; Tatjana Ž. Verbić; Miloš K. Milčić; Tamara R. Todorović; Ilija N. Cvijetić; Olivera R. Klisurić; Marina Radišić; Aleksandar D. Marinković
      Abstract: Publication date: Available online 1 September 2017
      Source:Arabian Journal of Chemistry
      Author(s): Aleksandra R. Božić, Nenad R. Filipović, Tatjana Ž. Verbić, Miloš K. Milčić, Tamara R. Todorović, Ilija N. Cvijetić, Olivera R. Klisurić, Marina Radišić, Aleksandar D. Marinković
      The substituent and solvent effect on intramolecular charge transfer (ICT) of twelve monocarbohydrazones (mCHs) were studied using experimental and theoretical methodology. The effects of specific and non-specific solvent–solute interactions on the UV-Vis absorption maxima shifts were evaluated using linear free energy relationships (LFERs) principles, i.e. using the Kamlet-Taft and Catalán models. Linear free energy relationships in the form of single substituent parameter equation (SSP) was used to analyze substituent effect on UV-Vis, NMR and pK a change. According to crystallographic data and quantum chemical calculations, the trans (E) form was found to be more stable. A photochromism of compounds with 2-hydroxyphenyl and 2-pyridylimino groups substituted at imine carbon atom results in E/Z isomerization due to creation of intermolecular hydrogen bond in E and Z form, respectively. Multiple stage mass spectrometry (MS-MSn) analysis was applied to define main fragmentation pathways. Furthermore, the experimental findings were interpreted with the aid of ab initio MP2/6-311G(d,p) and time-dependent density functional (TD-DFT) methods. TD-DFT calculations were performed to quantify the efficiency of intramolecular charge transfer (ICT) with the aid of the charge-transfer distance (DCT) and the amount of transferred charge (QCT) calculation. It was found that both substituents and solvents influence electron density shift i.e. extent of conjugation, and affect ICT character in the course of excitation.

      PubDate: 2017-09-06T14:51:18Z
      DOI: 10.1016/j.arabjc.2017.08.010
       
  • Design, synthesis, computational and biological evaluation of new
           benzodiazepines as CNS Agents

    • Authors: Shweta Verma; Surendra Kumar; Sushil Kumar
      Abstract: Publication date: Available online 31 August 2017
      Source:Arabian Journal of Chemistry
      Author(s): Shweta Verma, Surendra Kumar, Sushil Kumar
      Two series of new benzodiazepines were synthesized and the target compounds (E1-10 and G1-10) were evaluated for antianxiety and skeletal muscle relaxant activity as CNS agents in albino mice. The chemical structures of the compounds were confirmed on the basis of their TLC, IR, 1HNMR and13CNMR analysis. In computational studies, the physicochemical similarity of the target compounds was assessed by calculating from a set of physicochemical properties using software programs and test compounds demonstrated moderate physiochemical similarity with respect to diazepam. Log P values of the target compounds indicates good penetration to CNS. Molecular docking studies revealed that the target compounds correctly dock into the binding pocket of the GABAA receptor, while their bioavailability/drug-likeness was predicted to be acceptable but requires future optimization. The test compounds (E1-10 and G1-10) were screened for antianxiety and skeletal muscle relaxant activity using Elevated plus maze and Rotarod method respectively. Among them, the compounds E10 and G7 showed maximum potency as CNS agents.

      PubDate: 2017-09-06T14:51:18Z
      DOI: 10.1016/j.arabjc.2017.08.005
       
  • Synthesis of enantiomerically pure glycerol derivatives containing an
           organochalcogen unit: in vitro and in vivo antioxidant activity

    • Authors: Patrick C. Nobre; Henrique A. Vargas; Caroline G. Jacoby; Paulo H. Schneider; Angela M. Casaril; Lucielli Savegnago; Ricardo F. Schumacher; Eder J. Lenardão; Daiana S. Ávila; Luiz B.L. Rodrigues Junior; Gelson Perin
      Abstract: Publication date: Available online 24 August 2017
      Source:Arabian Journal of Chemistry
      Author(s): Patrick C. Nobre, Henrique A. Vargas, Caroline G. Jacoby, Paulo H. Schneider, Angela M. Casaril, Lucielli Savegnago, Ricardo F. Schumacher, Eder J. Lenardão, Daiana S. Ávila, Luiz B.L. Rodrigues Junior, Gelson Perin
      We describe here the synthesis of enantiomerically pure chalcogenoethers obtained through the reaction of nucleophilic species of chalcogen (S, Se and Te), generated in situ from the respective diorganyl dichalcogenides, with (R)- and (S)-tosyl solketal. Furthermore, some of the chalcogenoethers were treated with acidic cation exchange resin Dowex-(H+) leading to the respective deprotected enantiomerically pure 3-phenylchalcogenyl-1,2-diols. In order to explore the biological potential of these molecules, the antioxidant activity of some organochalcogens was evaluated by several in vitro assays. Overall, the chalcogenoethers containing Te were better scavengers of DPPH and ABTS•+ radicals, had higher ferric reducing capacity and prevented lipid peroxidation. To analyze the effects of these compounds in vivo, we used the alternative model Caenorhabditis elegans. Chalcogenoethers treatment, especially (S)- and (R)-2,2-dimethyl-4-(phenylselanylmethyl)-1,3-dioxolane, conferred protection against the mortality-induced by hydrogen peroxide. Accordingly, these chalcogenoethers were able to modulate the antioxidant enzyme catalase. Notably, the compounds did not present toxicity in worm’s reproduction. To sum up, our study demonstrated that Te- containing chalcogenoethers were promising in vitro scavengers, while Se molecules were more prone to protect against a stressor in vivo. In this sense, the antioxidant activity of chalcogenoethers, especially with Se and Te, indicates that these molecules may have biological application in an attempt to reduce the oxidative stress.
      Graphical abstract image

      PubDate: 2017-08-31T13:50:56Z
      DOI: 10.1016/j.arabjc.2017.08.007
       
  • Biofouling resistant polyethylene cage aquaculture nettings: A new
           approach using polyaniline and nano copper oxide

    • Authors: P. Muhamed Ashraf; K.G. Sasikala; Saly N. Thomas; Leela Edwin
      Abstract: Publication date: Available online 24 August 2017
      Source:Arabian Journal of Chemistry
      Author(s): P. Muhamed Ashraf, K.G. Sasikala, Saly N. Thomas, Leela Edwin
      Biofouling in cage aquaculture netting causes clogging of meshes, increased stress and retards the growth of fishes. This paper describes a new method of protecting polyethylene cage nettings from biofouling using polyaniline and nano-copper oxide. Polyaniline was synthesized in-situ over polyethylene cage netting material and subsequently treated with nano copper oxide. The modified netting material exposed to estuarine environment exhibited excellent fouling resistance. FTIR characterization confirmed the formation of polyaniline and adsorption of nano copper oxide over the netting material. SEM and AFM evaluation showed uniform coating of polyaniline and nano copper oxide on the polyethylene-polyaniline (PE-PANI) matrix. The results highlight the potential application of polyaniline plus nano copper oxide coated polyethylene nettings in controlling biofouling in cage aquaculture.

      PubDate: 2017-08-31T13:50:56Z
      DOI: 10.1016/j.arabjc.2017.08.006
       
  • The application of FTIR in situ spectroscopy combined with methanol
           adsorption to the study of mesoporous sieve SBA-15 with cerium-zirconium
           oxides modified with gold and copper species

    • Authors: Piotr Kaminski
      Abstract: Publication date: Available online 20 August 2017
      Source:Arabian Journal of Chemistry
      Author(s): Piotr Kaminski
      The molecular sieves SBA-15 with ceria, zirconia and mixed cerium-zirconium oxides were synthesized and used as supports for gold and copper species. The materials were characterised using a FTIR in situ spectroscopy combined with the adsorption of methanol and oxygen as probe molecules, which allowed the monitoring of the changes on the surface, in particular the creation of the intermediates species on the active sites of materials. The presence of interactions between gold and copper in bimetallic catalysts was considered during the reaction of methanol oxidation. The goal of this work was studied the changes of intermediates adsorbed on the surface of catalysts during the oxidation of methanol after treatment at selected temperature. The monometallic gold and the bimetallic copper-gold catalysts were tested in the reaction of methanol oxidation in the gas phase in situ.
      Graphical abstract image

      PubDate: 2017-08-31T13:50:56Z
      DOI: 10.1016/j.arabjc.2017.08.004
       
  • Biosilica-nanogold composite: Easy-to-prepare catalyst for soman
           degradation

    • Authors: Veronika Holišová; Martin Urban; Marek Kolenčík; Yvonne Němcová; Adam Schröfel; Pavlína Peikertová; Jiří Slabotinský; Gabriela Kratošová
      Abstract: Publication date: Available online 18 August 2017
      Source:Arabian Journal of Chemistry
      Author(s): Veronika Holišová, Martin Urban, Marek Kolenčík, Yvonne Němcová, Adam Schröfel, Pavlína Peikertová, Jiří Slabotinský, Gabriela Kratošová
      A very fast single-step biosynthesis of gold nanoparticles (AuNPs) using algal cells of Mallomonas kalinae (MK) is introduced. The average particle size of crystalline AuNPs was approximately 10nm. Subsequently, the catalytic activity of two systems – MK-biosilica scales and MK-biosilica scales with AuNPs – was compared with a control hydrolysis of soman (GD) performed in demineralized water. The kinetics of GD degradation was studied using a gas chromatography with mass detector (GC–MS) and solid-phase microextraction. The residual content of GD was 3.8% and 3.5% for both initial concentrations of GD (68µgmL−1 and 340µgmL−1, respectively) after 48h of testing when nanogold was used asa catalyst. Experimental results confirmed the catalytic activity of biosynthesized AuNPs, as well as the role of biosilica itself in the degradation of GD.
      Graphical abstract image

      PubDate: 2017-08-31T13:50:56Z
      DOI: 10.1016/j.arabjc.2017.08.003
       
  • Structure-activity relationship of eight high content flavonoids analyzed
           with a preliminary assign-score method and their contribution to
           antioxidant ability of flavonoids-rich extract from Scutellaria
           baicalensis shoots

    • Authors: Ke Li; Hang Fan; Peipei Yin; Lingguang Yang; Qiang Xue; Xiang Li; Liwei Sun; Yujun Liu
      Abstract: Publication date: Available online 12 August 2017
      Source:Arabian Journal of Chemistry
      Author(s): Ke Li, Hang Fan, Peipei Yin, Lingguang Yang, Qiang Xue, Xiang Li, Liwei Sun, Yujun Liu
      Investigation of flavonoids-rich extract from Scutellaria baicalensis shoots shows that 15 of the 19 flavonoids detected with UPLC-Q-TOF-MS were identified, and it exhibited high antioxidant abilities with IC50 at 70.81, 35.34 and 33.27 μg/mL in DPPH, ABTS and CAA assays, respectively. An order of antioxidant abilities in scavenging DPPH• and ABTS+• of eight high content flavonoids in the extract was the same, and it could be well-explained by a preliminary assign-score method we created in structure-activity relationship analyses specific for flavonoids, revealing that double bonds and phenolic hydroxyls on rings A and B are augmentors, and sugar moiety is an attenuator influencing antioxidant capacity but might contribute positively in CAA assays. In addition, three of the eight flavonoids (baicalein, baicalin and scutellarin) made contributions of 58.33%, 60.36% and 51.41% to overall antioxidant activity of the flavonoids-rich extract in DPPH, ABTS and CAA assays, respectively, thus were determined as the primary or marker flavonoids of Scutellaria baicalensis shoots.

      PubDate: 2017-08-31T13:50:56Z
      DOI: 10.1016/j.arabjc.2017.08.002
       
  • Effect of the AACVD based synthesis atmosphere on the structural
           properties of multi-walled carbon nanotubes

    • Authors: Pawel Mierczynski; Oleksandr Shtyka; Marcin Kozanecki; Paulina Filipczak; Waldemar Maniukiewicz; Dmitry G. Gromov; Sergey V. Dubkov; Artem V. Sysa; Alexey Yu. Trifonov; Agnieszka Czylkowska; Malgorzata I. Szynkowska; Tomasz P. Maniecki
      Abstract: Publication date: Available online 10 August 2017
      Source:Arabian Journal of Chemistry
      Author(s): Pawel Mierczynski, Oleksandr Shtyka, Marcin Kozanecki, Paulina Filipczak, Waldemar Maniukiewicz, Dmitry G. Gromov, Sergey V. Dubkov, Artem V. Sysa, Alexey Yu. Trifonov, Agnieszka Czylkowska, Malgorzata I. Szynkowska, Tomasz P. Maniecki
      The synthesis of multi-walled carbon nanotubes (MWCNTS) has been the focus of considerable research effort for more than twenty-five years and it continues to receive increasing attention because of its importance to produce carbon nanotubes with suitable parameters for future applications. To the best of our knowledge this study presents for the first time the complex studies concerning the effect of aerosol-assisted chemical vapour deposition (AACVD) process conditions (including temperature (750–1200°C) and the composition of the carrier gas (N2, Ar, He, 5% H2-95% Ar, 3% H2O-97% Ar)) on the conversion of the carbon source and on the properties of the carbon nanotubes. In addition, it was also found that oxidative or reductive atmosphere applied during the AACVD process have a great impact on the quality and the degree of toluene conversion into the carbon solids obtained during the synthesis. X-ray Diffraction (XRD), Specific Surface Area and Porosity analysis (BET), Scanning Electron Microscopy with Energy-Dispersive X-ray Spectroscopy (SEM-EDS), Transmission Electron Microscopy (TEM), Raman spectroscopy and Thermo-gravimetric Analysis (TG) were used to characterize the carbon nanotubes.

      PubDate: 2017-08-31T13:50:56Z
      DOI: 10.1016/j.arabjc.2017.08.001
       
  • Additions to non-activated alkenes: Recent advances

    • Authors: Dora Cristina Silva Costa
      Abstract: Publication date: Available online 4 August 2017
      Source:Arabian Journal of Chemistry
      Author(s): Dora Cristina Silva Costa
      Non-activated olefins represent one of the most explored platform in organic synthesis affording new and useful compounds with several biological applications, among others. The typical reactivity of these compounds is the addition-type reactions. A plethora of transformations and studies were reported in the literature by many research groups. The focus of this review is to organize and describe the most recent synthetic transformations of non-activated alkenes in organic synthesis. Therefore, it is divided into five sections corresponding to each type of the products obtained: synthesis of fluoro-, chloro- and bromo-compounds; synthesis of alkyl/vinyl/aryl/heteroaryl compounds; synthesis of phospho/sulfur/silyl/cyano-compounds; synthesis of amine/amide/oxygenated compounds and synthesis of other functionalized compounds.

      PubDate: 2017-08-31T13:50:56Z
      DOI: 10.1016/j.arabjc.2017.07.017
       
  • Enhanced catalytic activity of composites of NiFe2O4 and nano cellulose
           derived from waste biomass for the mitigation of organic pollutants

    • Authors: Kanu Gupta; Anupama Kaushik; K.B. Tikoo; Vinod Kumar; Sonal Singhal
      Abstract: Publication date: Available online 3 August 2017
      Source:Arabian Journal of Chemistry
      Author(s): Kanu Gupta, Anupama Kaushik, K.B. Tikoo, Vinod Kumar, Sonal Singhal
      This study reports facile in situ synthesis of magnetically retrievable nanocomposites of nanocellulose (derived from waste biomass) and NiFe2O4 nanoparticles using hydrothermal method. The synthesized nanocomposites were characterized using various techniques such asFT-IR, powder XRD, HR-TEM, BET and VSM. The characterization of nanocomposites clearly revealed that NiFe2O4 nanoparticles were well dispersed on the surface of cellulose nanofibres. The catalytic performance of the synthesized nanocomposites was assessed for both the photocatalytic oxidation and reduction of organic pollutants. The prepared nanocomposites displayed excellent catalytic performance in comparison to pristine NiFe2O4 nanoparticles due to stabilization and increased dispersability of NiFe2O4 nanoparticles on the cellulose matrix. The present work promotes the use of bio based renewable sources to fabricate environment friendly materials to be used in the field of catalysis for the abatement of organic pollutants.
      Graphical abstract image

      PubDate: 2017-08-31T13:50:56Z
      DOI: 10.1016/j.arabjc.2017.07.016
       
  • Structure and composition peculiarities and spectral-luminescent
           properties of colorless and pink Bi4Ge3O12 scintillation crystals

    • Authors: G.M. Kuz'micheva; I.A. Kaurova; L.I. Ivleva; E.V. Khramov; P.A. Eistrikh-Geller; V.B. Rybakov; T.V. Chukhlovina; S.V. Firstov
      Abstract: Publication date: Available online 2 August 2017
      Source:Arabian Journal of Chemistry
      Author(s): G.M. Kuz'micheva, I.A. Kaurova, L.I. Ivleva, E.V. Khramov, P.A. Eistrikh-Geller, V.B. Rybakov, T.V. Chukhlovina, S.V. Firstov
      Czochralski-grown colorless and pink Bi4Ge3O12 (BGO) single crystals have been characterized by the X-ray diffraction, X-ray absorption, and luminescence and optical spectroscopy. Additional high-temperature vacuum annealing of the as-grown colorless crystal at 900–950°C using a special reducing agent leds to the appearance of pink coloration and modification of its properties. The refinement of actual compositions of both BGO crystals showed the distribution of the Bi3+ions over two, tetrahedral and octahedral, sites, the Bi content in the colorless crystal being greater and lower in the octahedral and tetrahedral sites, respectively, compared with the colored crystal. A small amount of Bi5+ions was revealed in the tetrahedral sites of the colorless crystal. Oxygen vacancies, as a part of the color center responsible for the crystal coloration, were found in the structure of pink sample. The pink BGO crystal is characterized by photoluminescence in the near infra-red spectral range.

      PubDate: 2017-08-31T13:50:56Z
      DOI: 10.1016/j.arabjc.2017.07.015
       
  • Amino acids and their derivatives as corrosion inhibitors for metals and
           alloys

    • Authors: B. El Ibrahimi; A. Jmiai; L. Bazzi; S. El Issami
      Abstract: Publication date: Available online 31 July 2017
      Source:Arabian Journal of Chemistry
      Author(s): B. El Ibrahimi, A. Jmiai, L. Bazzi, S. El Issami
      In the last two decades, research in the field of corrosion inhibitors had been directed toward the goal of using cheap effective molecules of low or non-negative environmental impact to replace the environmentally hazardous compounds. One of the encourager compounds which can be used as safe corrosion inhibitors are amino acids. They are environmentally friendly, non-toxic, biodegradable and relatively cheap. On other hand, the development of computational modeling helps to understand the inhibition mechanism of those compounds and to develop the newly designed inhibitors. In this review, most of contribution made in literature on the use of amino acids and their derivatives as corrosion inhibitors for metallic alloys materials were presented and discussed.

      PubDate: 2017-08-31T13:50:56Z
      DOI: 10.1016/j.arabjc.2017.07.013
       
  • Oxidative dehydrogenation of ethylbenzene over γ-Al2O3 supported
           ceria-lanthanum oxide catalysts: Influence of Ce/La composition

    • Authors: Venkata Rao Madduluri; Venkateshwarlu Velpula; Thirupathaiah Ketike; Ashok Raju Muppala; Nagaiah Peddinti; Murali Kondeboina; David Raju Burri; Seetha Rama Rao Kamaraju
      Abstract: Publication date: Available online 31 July 2017
      Source:Arabian Journal of Chemistry
      Author(s): Venkata Rao Madduluri, Venkateshwarlu Velpula, Thirupathaiah Ketike, Ashok Raju Muppala, Nagaiah Peddinti, Murali Kondeboina, David Raju Burri, Seetha Rama Rao Kamaraju
      A series of CeO2/γ-Al2O3 (CA) catalysts with CeO2 loading of 5, 10, 15 and 20wt% were prepared by a facile incipient wetness impregnation technique. Another series of La3+ doped catalysts (LCA) were prepared, wherein, 1, 3 and 5wt% of La2O3 was doped in 15wt%CeO2/γ-Al2O3, which were designated as 1LCA, 3LCA and 5LCA catalysts. Both CA and LCA catalysts were characterized by thermogravimetric analysis (TGA), BET surface area, X-ray diffraction (XRD), Infrared (FT-IR) spectroscopy, UV–vis diffuse reflectance spectra (UV–vis DRS), transmission electron microscopy (TEM), temperature programmed desorption of NH3 (TPD of NH3) temperature programmed reduction (TPR), CO2 pulse chemisorption and O2 pulse chemisorption techniques. All CA and LCA catalysts were evaluated for ethylbenzene (EB) oxidative dehydrogenation to styrene (ST) in vapor phase under atmospheric pressure with CO2 as an oxidant. Albeit CA and LCA catalysts are active, 15CA and 3LCA catalysts are found to be the best catalysts of the respective series. Apart from compatible acid-base and redox characteristics, sufficient amount of solid solution clusters (CexLa1-xO2-δ) are responsible for superior activity of 3LCA catalyst.
      Graphical abstract image

      PubDate: 2017-08-31T13:50:56Z
      DOI: 10.1016/j.arabjc.2017.07.014
       
  • 2,3-Dichloroquinoxaline as a versatile building block for heteroaromatic
           nucleophilic substitution: A review of the last decade

    • Authors: Jannyely M. Neri; Lívia N. Cavalcanti; Renata M. Araújo; Fabrício G. Menezes
      Abstract: Publication date: Available online 29 July 2017
      Source:Arabian Journal of Chemistry
      Author(s): Jannyely M. Neri, Lívia N. Cavalcanti, Renata M. Araújo, Fabrício G. Menezes
      Nucleophilic aromatic substitution (SNAr) is a class of reaction that has become very important over time. This type of transformation usually proceeds without the use of metal catalysts, making it very important for pharmaceutical and industrial purposes. Nevertheless, in order to obtain the desired substituted product, activated substrates are required to allow SNAr reactions under mild conditions. In this context, quinoxaline derivatives are one class of N-heteroarenes that has attracted great attention from the scientific community because of the large variety of applications for their derivatives in many fields, such as biological and technological areas. There are several reported methods for the synthesis of quinoxaline derivatives. Nonetheless, reactions of 2,3-dichloroquinoxaline (DCQX) with nucleophilic species has become a viable alternative because of the possibility to form new carbon-heteroatom bonds (e.g. CO, CN, and CS) directly at C2 and/or C3 positions of the quinoxaline moiety. This current review brings an overview of the last decade on the remarkable versatility of DCQX as a substrate for SNAr reactions. Herein, we show several examples in which DCQX reacts with N-, O-, S-, P- and C-nucleophiles, including controlled processes for the selective formation of mono- and disubstituted substrates. Almost all polyfunctionalized quinoxalines synthesized using this approach have shown applications in different areas such as in biological and technological fields.
      Graphical abstract image

      PubDate: 2017-08-31T13:50:56Z
      DOI: 10.1016/j.arabjc.2017.07.012
       
  • Combustion synthesized crystalline La-Mn perovskite catalysts: Role of
           fuel molecule on thermal and chemical events

    • Authors: Ramzi Hammami; Habib Batis
      Abstract: Publication date: Available online 28 July 2017
      Source:Arabian Journal of Chemistry
      Author(s): Ramzi Hammami, Habib Batis
      Solution combustion synthesis (SCS) technique was applied to produce LaMnO3+δ with the aim to investigate the effect of the chemical nature of a series of six fuel molecules (glycine, maleic acid, succinic acid, citric acid, acetic acid, urea) on the combustion reaction mechanism and physicochemical properties of the as-prepared powders. The whole SCS process was found to involve two types of combustion reactions depending on the used sacrificial molecules. Type I (with glycine, maleic acid and succinic acid) was characterized by a one-step exothermic reaction implying a semi-decomposed mixed nitrate-fuel complex and NO2 arising from manganese nitrate decomposition. The heat emission allows reaching the temperature suitable for well crystallized as-prepared perovskite powders. Type II (with citric acid, acetic acid and urea) was typified by a multi stage process in which intermediate decomposition reactions occurred before the formation of a mixed nitrate-fuel complex. In this case, the heat emission became lower than that expected from stoichiometric reaction, thus limiting the completion of the direct reaction for perovskite production. Consequently, part (with citric acid and acetic acid) or totally (with urea) of lanthanum and manganese remained distinctly combined in two amorphous phases (La(OH)2NO3, MnOx) that were intimately mixed. With respect to other fuels, combustion synthesis, using glycine, produced better crystallized, more defective and performant catalytic perovskite phase toward deep ethanol oxidation.

      PubDate: 2017-08-31T13:50:56Z
      DOI: 10.1016/j.arabjc.2017.07.009
       
  • Growth kinetic study of ionic liquid mediated synthesis of gold
           nanoparticles using Elaeis guineensis (oil palm) kernels extract under
           microwave irradiation

    • Authors: Muhammad Irfan; Muhammad Moniruzzaman; Tausif Ahmad; Pradip Chandra Mandal; Bawadi Abdullah; Sekhar Bhattacharjee
      Abstract: Publication date: Available online 28 July 2017
      Source:Arabian Journal of Chemistry
      Author(s): Muhammad Irfan, Muhammad Moniruzzaman, Tausif Ahmad, Pradip Chandra Mandal, Bawadi Abdullah, Sekhar Bhattacharjee
      Gold nanoparticles (AuNPs) are the most studied nanomaterials due to their promising applications. However, surface capping of AuNPs is essential to protect aggregation for enhanced colloidal stability. In this study, a single step method was established to synthesize stable AuNPs using oil palm kernel (OPK) extract prepared in IL[EMIM][OAc] (1-ethyl-3-methylimidazolium acetate). Ionic liquids were used for phytochemicals extraction along with capping and stabilizing of AuNPs after their synthesis. The OPK extract reduced the gold precursor, and UV–vis spectroscopy revealed a sharp surface plasmon (SPR) peaks in the region of 524–529nm, which confirmed the formation of AuNPs. UV–vis and TEM analysis indicated that microwave assisted synthesis was rapid to synthesize well dispersed and small sized AuNPs in comparison with conventional heating. FTIR analysis of kernels extract before and after its reaction with gold precursor identified the involvement of CH aromatic groups, polyphenolic OH groups, and carbonyl amide groups that are responsible for reduction of trivalent gold ions to AuNPs. EDAX and XPS analysis were performed to identify the elemental gold and its surface interaction with ILs and other organic moieties. Colloidal AuNPs kept at room temperature for periods of six months were remained stable. The change of pristine nanostructure arises due to involvement of different driving forces during growth of nanoparticles. Thermodynamically instability of nanomaterials may leads to Ostwald Repining (OR) or adopt complex pattern of growth and undergo coalesce and orientation attachment (OA). These models were fitted to compare the theoretically growth of particles along with actual increase of particles size. Experimental results suggested that OA growth was originated in early phase, however, it substituted and mainly controlled by OR growth pattern over time.

      PubDate: 2017-08-31T13:50:56Z
      DOI: 10.1016/j.arabjc.2017.07.005
       
  • Removal of multi-metals from water using reusable pectin/cellulose
           microfibers composite beads

    • Authors: Emanuele F. Lessa; Aline L. Medina; Anderson S. Ribeiro; André R. Fajardo
      Abstract: Publication date: Available online 27 July 2017
      Source:Arabian Journal of Chemistry
      Author(s): Emanuele F. Lessa, Aline L. Medina, Anderson S. Ribeiro, André R. Fajardo
      Pectin (Pec) and cellulose microfibers (CF) extracted from orange waste were combined to form composite beads with enhanced adsorption capacity. Such beads were extensively tested in the removal of multi-metal ions from water. A factorial design approach was conducted to establish the optimum conditions for adsorption of Cd(II), Cu(II), and Fe(II) on Pec-CF beads. Batch adsorption experiments revealed that removal efficiency of such metal ions falls in the range of 94–58% and it followed the order Fe(II) > Cu(II) > Cd(II). The maximum Cd(II), Cu(II) and Fe(II) adsorption capacities calculated from the Langmuir isotherm were 192.3, 88.5 and 98.0 mg/g, respectively. FTIR analysis suggests that the functional groups on Pec-CF beads (binding sites) favor the adsorption of such metal ions. Desorption and reuse experiments demonstrated the beads could be used for at least five consecutive adsorption/desorption cycles. Our finds suggest the Pec-CF beads can serve as an efficient adsorbent for the removal of multi-metal ions from wastewater.
      Graphical abstract image

      PubDate: 2017-07-27T12:36:01Z
      DOI: 10.1016/j.arabjc.2017.07.011
       
  • Design and Nonlinear Optical Properties (NLO) using DFT Approach of New Cr
           (III), VO(II), and Ni(II) Chelates Incorporating Tri-dentate Imine Ligand
           for DNA Interaction, Antimicrobial, Anticancer Activities and Molecular
           Docking Studies

    • Authors: Laila H. Abdel-Rahman; Ahmed M. Abu-Dief; H. Moustafa; Azza A. Hassan Abdel-Mawgoud
      Abstract: Publication date: Available online 25 July 2017
      Source:Arabian Journal of Chemistry
      Author(s): Laila H. Abdel-Rahman, Ahmed M. Abu-Dief, H. Moustafa, Azza A. Hassan Abdel-Mawgoud
      In recent years, metals based antitumor complexes have played a vital role in chemotherapy. Therefore, in this study, some new imine Cr(III), VO(II) and Ni(II) complexes incorporating ESAP imine ligand (2- Ethoxy-6-((2-hydroxy-phenylimino)- methyl)-phenol were designed and synthesized. The investigated complexes were fully characterized by micro analysis, infrared, electronic spectra, thermal analysis (TGA), conductivity as well as magnetic susceptibility measurements. Moreover, the stability constants of the prepared complexes were determined spectrophotometrically. The results suggest that the titled ESAP imine ligand serves as tri-dentate moiety through deprotonated two phenolic oxygen and azomethene nitrogen atoms for coordination to Cr(III) in octahedral geometry, tetrahedral to Ni(II) and distorted square pyramidal to VO (II). The electronic structure and nonlinear optical parameters NLO of the newly synthesized complexes are investigated theoretically at the B3LYP/GEN level of theory. The studied complexes show promising optical properties. Indeed, the prepared compounds were evaluated for antimicrobial effect against some types of bacteria and fungi. The investigated complexes exhibit a stronger antimicrobial efficiency compared to its ligand. Moreover, the interaction of the complexes with CT-DNA was monitored using spectral studies, viscosity and gel electrophoreses measurements. Furthermore, the cytotoxic activity of the prepared imine complexes on human colon carcinoma cells, hepatic cellular carcinoma cells and breast carcinoma cells have shown promising results and enhancement of the anti-proliferative activity compared to its ligand. The molecular docking into TRK (PDB: 1t46) was done for the optimization of the investigated compounds as potential TRK inhibitors.
      Graphical abstract image

      PubDate: 2017-07-27T12:36:01Z
      DOI: 10.1016/j.arabjc.2017.07.007
       
  • Curcumin-loaded layer-by-layer folic acid and casein coated carboxymethyl
           cellulose/casein nanogels for treatment of skin cancer

    • Authors: P. Priya; R. Mohan Raj; V. Vasanthakumar; V. Raj
      Abstract: Publication date: Available online 22 July 2017
      Source:Arabian Journal of Chemistry
      Author(s): P. Priya, R. Mohan Raj, V. Vasanthakumar, V. Raj
      Targeted drug delivery systems using natural polysaccharide/protein biopolymer for tumor cells are an attractive platform for enriching the therapeutic effects and reducing the side effects of the drug. Carboxymethyl cellulose (CMC) and casein (CA) nanogels (NGs) loaded with curcumin (CUR) were prepared by self-assembly method and fabricated with folic acid (FA) and casein using layer-by-layer (LbL) technique for skin cancer drug delivery. The prepared samples were characterized by techniques like zeta potential, FTIR, XRD, TGA and Cryo-SEM. Both the swelling and in vitro drug release was performed in acidic pH (4.5 & 6.8) and physiological pH 7.4. Hemolysis assays demonstrated that the drug carriers are hemocompatible. Confocal microscope studies indicate facilitated uptake of 2-FA/CA/CUR@CMC-CA NGs in MEL-39 melanoma cancer cell line, which in turn result in a higher potential for apoptosis. Compared to pure CUR and CUR@CMC-CA NGs, the 2-FA/CA/CUR@CMC-CA NGs has lower IC50 value and superior cytotoxicity in MEL-39 cells because of folate-receptor mediated endocytosis evaluated by the cellular viability quantification using MTT assay and optical microscope images. Finally from in vitro skin permeation experiments, 2-FA/CA/CUR@CMC-CA NGs showed 3.47 ± 0.03 to 4.15 ± 0.25 μg/ml CUR concentrations at the stratum corneum, epidermal and dermal layers. Overall, our results put forth 2-FA/CA/CUR@CMC-CA NGs as an aspiring candidate to achieve enhanced anticancer effects against melanoma skin cancer.

      PubDate: 2017-07-27T12:36:01Z
      DOI: 10.1016/j.arabjc.2017.07.010
       
  • Curing and thermal degradation of diglycidyl ether of bisphenol A epoxy
           resin crosslinked with natural hydroxy acids as environmentally friendly
           hardeners

    • Authors: N. Tudorachi; F. Mustata
      Abstract: Publication date: Available online 21 July 2017
      Source:Arabian Journal of Chemistry
      Author(s): N. Tudorachi, F. Mustata
      The paper presents the curing of diglycidyl ether of bisphenol A (DGEBA) with two natural hydroxy acids and the thermal behavior of the cured products. The kinetics of the curing reactions were evaluated from the differential scanning calorimetry (DSC) curves using Ozawa, Kissinger methods and “Thermokinetics-3” software (Netzsch). Thermal decomposition behavior of the cured products up to 600 °C (in nitrogen) was made using simultaneous TG/FT-IR/MS technique. The kinetic parameters were obtained using the same software which shows that the thermal degradation takes place in three or four consecutive steps. The chemical composition of gases evolved at the thermal decomposition has been identified using FT-IR and MS techniques. The main products are: water, carbon dioxide, acids, anhydrides, aliphatic and aromatic hydrocarbons.

      PubDate: 2017-07-21T11:32:36Z
      DOI: 10.1016/j.arabjc.2017.07.008
       
  • Physical properties, biological applications and biocompatibility studies
           on biosynthesized single phase cobalt oxide (Co3O4) nanoparticles via
           Sageretia thea (Osbeck.)

    • Authors: Ali Talha Khalil; Muhammad Ovais; Ikram Ullah; Muhammad Ali; Zabta Khan Shinwari; Malik Maaza
      Abstract: Publication date: Available online 19 July 2017
      Source:Arabian Journal of Chemistry
      Author(s): Ali Talha Khalil, Muhammad Ovais, Ikram Ullah, Muhammad Ali, Zabta Khan Shinwari, Malik Maaza
      Cobalt oxide nanoparticles were successfully biosynthesized by complete green process using aqueous leaf extracts of Sageretia thea as chelating agent. Diverse techniques were applied for characterization. Antibacterial (with and without UV illumination), antileishmanial, antioxidant and enzyme inhibition applications were assessed, while freshly isolated macrophages and red blood cells were used for biocompatibility studies. Good antibacterial nature and enhancement of bactericidal nature upon UV modulation is reported. Staphylococcus aureus and Escherichia coli are indicated as most susceptible bacterial strains. Significant cytotoxic potential is revealed with IC50 calculated as 12.82 µg/ml and 3.16 µg/ml against the axenic leishmanial promastigote and amastigote cultures respectively. Biogenic cobalt oxide nanoparticles indicated DPPH free radical scavenging potential, while moderate antioxidant capacity and reducing power was demonstrated. Bioinspired cobalt oxide also demonstrated alpha amylase and protein kinase inhibition at higher concentrations. Biogenic cobalt oxide was found as more cytotoxic to macrophages (IC50=58.55 µg/ml) then to RBC’s (IC50> µg/ml). Our results indicate green synthesis as an alternative, effective and eco-friendly method for the biosynthesis of cobalt oxide nanoparticles with numerous biological applications.
      Graphical abstract image

      PubDate: 2017-07-21T11:32:36Z
      DOI: 10.1016/j.arabjc.2017.07.004
       
  • Quinoline derivatives as possible lead compounds for anti-malarial drugs:
           spectroscopic, DFT and MD study

    • Authors: B. Sureshkumar; Y. Sheena Mary; C. Yohannan Panicker; S. Suma; Stevan Armaković; Sanja J. Armaković; C. Van Alsenoy; B. Narayana
      Abstract: Publication date: Available online 18 July 2017
      Source:Arabian Journal of Chemistry
      Author(s): B. Sureshkumar, Y. Sheena Mary, C. Yohannan Panicker, S. Suma, Stevan Armaković, Sanja J. Armaković, C. Van Alsenoy, B. Narayana
      In this work we report spectroscopic characterization and reactivity study by density functional theory (DFT) and molecular dynamics (MD) simulations of two quinoline derivatives. Collected computational results for the two new derivatives have been compared with the pristine quinoline in order to investigate the consequences of modifications by introduction of chlorine atoms and methyl and OH groups. Potential energy distribution (PED) analysis has been performed in order to assign principal vibrational numbers. DFT calculations have been used to obtain global and local quantum-molecular descriptors including frontier molecular orbitals, charge distribution by molecular electrostatic potential (MEP) surface, average local ionization energy (ALIE) surface, and Fukui functions. Natural bond order (NBO) analysis has been performed in order to investigate hyper-conjugative properties. To investigate sensitivity towards autoxidation and hydrolysis we have calculated bond dissociation energies (BDE) and radial distribution functions (RDF). Molecular docking study has also been performed in order to initially assess the potential of target molecules to bind with dehydrogenase inhibitor and these quinoline derivatives can be a lead compounds for developing new anti-malarial drug.

      PubDate: 2017-07-21T11:32:36Z
      DOI: 10.1016/j.arabjc.2017.07.006
       
  • Degradation of PLA/ZnO and PHBV/ZnO composites prepared by melt processing

    • Authors: Alojz Anžlovar; Andrej Kržan; Ema Žagar
      Abstract: Publication date: Available online 12 July 2017
      Source:Arabian Journal of Chemistry
      Author(s): Alojz Anžlovar, Andrej Kržan, Ema Žagar
      Composites of polylactide (PLA) or poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and ZnO nanoparticles (nZnO) were prepared by melt processing. During extrusion and moulding nano ZnO formed aggregates with sizes between 0.5 and 5 μm in PLA and between 0.5 and 15 μm in PHBV. Nano ZnO acted as a disruptor of PLA crystallization process and shifted the polymer glass transition temperature to lower temperatures. This was explained by degradation of PLA polymer chains during melt processing. SEC, FTIR and 1H NMR confirmed that PLA degradation was correlated to nZnO concentration. The effect of nZnO on crystallization of PHBV matrix was much less intense which was shown by TGA. On the other hand, PHBV showed significantly lower thermal stability than PLA. ZnO participated as a reactant and an accelerator in the degradation reaction of PLA and at a smaller extent with PHBV. The results of this study revealed that addition of pure nZnO in concentrations higher than 0.1 wt.% is not recommended for the preparation of PLA/nZnO composites by melt processing while in the case of PHBV the nZnO concentration may be higher but it should not exceed 1.0 wt.%. The exposure time of these materials to high temperatures during melt processing should also be minimized.

      PubDate: 2017-07-21T11:32:36Z
      DOI: 10.1016/j.arabjc.2017.07.001
       
  • Hierarchical zinc aluminate 3D nanostructures, synthesized by bio-inspired
           ultrasound assisted sonochemical route: Display and dosimetry applications
           

    • Authors: F. Femila Komahal; H. Nagabhushana; G.P. Darshan; B. Daruka Prasad
      Abstract: Publication date: Available online 11 July 2017
      Source:Arabian Journal of Chemistry
      Author(s): F. Femila Komahal, H. Nagabhushana, G.P. Darshan, B. Daruka Prasad
      ZnAl2O4:Tb3+ (0.25 - 5 mol %) nanophosphor were synthesized by ultrasound assisted sonochemical route using bio-sacrificial Aloe Vera (A.V.) gel as a template. The effect of sonication time, A.V. gel concentration, pH value, sonication power and temperature on the morphologies of the prepared samples were systematically explored and discussed. Probable formation mechanism for various morphologies of ZnAl2O4:Tb3+ nanophosphor was discussed. Structural and luminescence properties of the obtained samples were thoroughly investigated. Rietveld refinement of the prepared samples exhibit cubic structure with Fd 3 ¯ m space group. Thermoluminescence (TL) glow curves exhibit a well resolved glow peak at ∼ 197 C. TL intensity was found to increase linearly up to 1 kGy and thereafter it shows sub-linear behavior with increase of dose which indicates that the present phosphor was quite useful for TL dosimetry. Kinetic parameters related with the glow peaks were estimated by different methods. Photoluminescence (PL) spectra shows the characteristic Tb3+ ion peaks at ∼ 488 nm, 542 nm, 584 nm and 622 nm corresponding to 5D4→7FJ (J = 3, 4, 5 and 6) transitions respectively. The chromaticity co-ordinates of all the phosphors were well located in green region. Therefore, the present phosphor was quite useful as green component of white light- emitting diodes.

      PubDate: 2017-07-21T11:32:36Z
      DOI: 10.1016/j.arabjc.2017.07.002
       
  • Studies on the development of activated binary clay and corrosion
           monitoring using embedded sensor

    • Authors: Han-Seung Lee; Seung-Jun Kwon; Subbiah Karthick; Velu Saraswathy; Srinivasan Muralidharan
      Abstract: Publication date: Available online 11 July 2017
      Source:Arabian Journal of Chemistry
      Author(s): Han-Seung Lee, Seung-Jun Kwon, Subbiah Karthick, Velu Saraswathy, Srinivasan Muralidharan
      Bentonite and marconite are the low resistance moisture retaining conductive backfill materials used in earthing applications.Both the products contains some drawbacks: bentonite has limited moisture retaining capacity and marconite has 15-20% impurities which will corrode the earth connections resulting in the loss of the system which are found to be very expensive. Taking into consideration of the above drawbacks, the present study aimed at developing a cost effective and highly conductive backfill material for earthing application with improved performance. For this study, commercially available bentonite and metakaolin (binary) clay was activated through physical, chemical and thermal treatments and the corrosion performance of binary clay was evaluated by using mild steel (MS) and galvanized (GI) steel Among the three activation methods, chemical activation method was found beneficial for mild steel in binary clay media. The conductivity of the chemically activated clay was 204.7 mS/cm, pH was 12.58, and the particle size distribution was found to be 40 to 50 µm indicates the better corrosion resistance and quite suitable for earthing applications. Chemical activation of the clay mainly involves the breaking of bonds and dissolution of the three-dimensional network structure of glass which in turn cause Na+ ions move closer to the center point of crystal structure and the solubility of SiO2 in clay markedly increases. Potential-time studies showed that galvanizing loses its coating property within ten days in all the three type of clays used. Activation process significantly reduced the corrosion rate (3 and 6 times) in the case of thermally activated (TAC) and chemically activated clay (CAC) respectively. Earth excavation studies were conducted to monitor the corrosion of MS and GI using embedded MnO2 sensor. This investigation opens up a lot of scope for utilizing activated binary clay for all earthing applications.

      PubDate: 2017-07-21T11:32:36Z
      DOI: 10.1016/j.arabjc.2017.07.003
       
  • Inside Front Cover - Editorial Board

    • Abstract: Publication date: July 2017
      Source:Arabian Journal of Chemistry, Volume 10, Issue 5


      PubDate: 2017-06-20T05:49:34Z
       
 
 
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