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Journal Cover Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
  [SJR: 0.628]   [H-I: 64]   [7 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1386-1425
   Published by Elsevier Homepage  [2970 journals]
  • Photophysical performance comparison between bulk Cu(I) complex and its
           electrospinning fibers: Synthesis and characterization
    • Abstract: Publication date: 5 December 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 169
      Author(s): Wan Pu, Zhao Yuqing, Wang Lisha
      In this report, a diamine ligand having an electron-pulling group in its conjugation plane was designed. A methyl group was connected with this diamine ligand, hoping to further increase its steric hindrance. Its Cu(I) complex was synthesized and characterized by NMR, single crystal analysis and photophysical analysis. There was a distorted tetrahedral coordination field in this Cu(I) complex. Its onset electronic transition owned a mixed character of metal-to-ligand-charge-transfer which suffered from bad geometric relaxation. To limit this geometric relaxation and improve emissive performance, this Cu(I) complex was doped into a polymer host through electrospinning technique. Photophysical comparison between solid state sample, solution sample and composite samples indicated that excited state geometric relaxation was effectively limited by polymer immobilization effect, resulting in improved emissive performance, such as emission blue shift, long emission decay lifetime and better photostability.
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      PubDate: 2016-06-18T21:51:29Z
       
  • A colorimetric and fluorescence enhancement anion probe based on coumarin
           compounds
    • Abstract: Publication date: 5 December 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 169
      Author(s): Limin Zhao, Ge Liu, Baofeng Zhang
      In this paper, anion probe 1 was designed and synthesized by using phenprocoumon containing acyl hydrazine with p-nitro azo salicylaldehyde reaction Dickson et al. (2008) Dickson et al. (2008) [1] . In the anion probe 1, the nitro moiety is a signaling group and the phenolic hydroxyl moiety is anion binding site. Then the anion probe 1 was characterized by mass spectra (MS) and infrared spectra (IR). The binding properties of the anion probe 1 for anions such as F−, AcO−, H2PO4 −, OH−, Cl−, Br− and I− were investigated by ultraviolet-visible (UV–Vis) spectra and fluorescence spectra Shao et al. (2008) Shao et al. (2008) [2] . Furthermore, the color of anion probe 1 after addition of F−, AcO−, H2PO4 − and OH− in DMSO changed from yellow to blue, while no obvious color changes were observed by addition of other tested anions. Accordingly, the anion probe 1 could sense visually F−, AcO−, H2PO4 − and OH− without resorting to any spectroscopic instrumentation Amendola et al. (2010) Amendola et al. (2010) [3] .
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      PubDate: 2016-06-18T21:51:29Z
       
  • A fluorescence turn-on chemosensor for hydrogen sulfate anion based on
           quinoline and naphthalimide
    • Abstract: Publication date: 5 December 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 169
      Author(s): Zaoli Luo, Kai Yin, Zhu Yu, Mengxue Chen, Yan Li, Jun Ren
      A new fluorescence turn-on chemosensor 1 based on quinoline and naphthalimide was prepared and its anion sensing toward various anions behavior was explored in this paper. Sensor 1 exhibited a highly selective fluorescent response toward HSO4 − with an 8-fold fluorescence intensity enhancement in the presence of 10equiv. of HSO4 − in DMSO-H2O (1/1, v/v) solution. The sensor also displayed high sensitivity to hydrogen sulfate and the detection limit was calculated to be 7.79×10−7 M. The sensing mechanism has been suggested to proceed via a hydrolysis process of the Schiff base group. The hydrolysis product has been isolated and further identified by 1H NMR and MS.
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      PubDate: 2016-06-18T21:51:29Z
       
  • Full spectrum and selected spectrum based multivariate calibration methods
           for simultaneous determination of betamethasone dipropionate, clotrimazole
           and benzyl alcohol: Development, validation and application on commercial
           dosage form
    • Abstract: Publication date: 5 December 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 169
      Author(s): Hany W. Darwish, Eman S. Elzanfaly, Ahmed S. Saad, Abdelaziz El-Bayoumi Abdelaleem
      Five different chemometric methods were developed for the simultaneous determination of betamethasone dipropionate (BMD), clotrimazole (CT) and benzyl alcohol (BA) in their combined dosage form (Lotriderm® cream). The applied methods included three full spectrum based chemometric techniques; namely principal component regression (PCR), Partial Least Squares (PLS) and Artificial Neural Networks (ANN), while the other two methods were PLS and ANN preceded by genetic algorithm procedure (GA-PLS and GA-ANN) as a wavelength selection procedure. A multilevel multifactor experimental design was adopted for proper construction of the models. A validation set composed of 12 mixtures containing different ratios of the three analytes was used to evaluate the predictive power of the suggested models. All the proposed methods except ANN, were successfully applied for the analysis of their pharmaceutical formulation (Lotriderm® cream). Results demonstrated the efficiency of the four methods as quantitative tool for analysis of the three analytes without prior separation procedures and without any interference from the co-formulated excipient. Additionally, the work highlighted the effect of GA on increasing the predictive power of PLS and ANN models.
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      PubDate: 2016-06-18T21:51:29Z
       
  • Photocatalytic activity enhancement of anatase–graphene
           nanocomposite for methylene removal: Degradation and kinetics
    • Abstract: Publication date: 5 October 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 167
      Author(s): Mostafa Rezaei, Shiva Salem
      In the present research, the TiO2–graphene nanocomposite was synthesized by an eco-friendly method. The blackberry juice was introduced to graphene oxide (GO) as a reducing agent to produce the graphene nano-sheets. The nanocomposite of anatase–graphene was developed as a photocatalyst for the degradation of methylene blue, owing to the larger specific surface area and synergistic effect of reduced graphene oxide (RGO). The UV spectroscopy measurements showed that the prepared nanocomposite exhibited an excellent photocatalytic activity toward the methylene blue degradation. The rate of electron transfer of redox sheets is much higher than that observed on GO, indicating the applicability of proposed method for the production of anatase-RGO nanocomposite for treatment of water contaminated by cationic dye. The prepared materials were characterized with Fourier transform infrared spectroscopy, X-ray diffraction, Brunauer–Emmett–Teller surface area measurement, scanning electron microscopy and transmission electron microscopy. A facile and rapid route was applied for the uniform deposition of anatase nanoparticles on the sheets. The resulting nanocomposite contained nanoparticles with a mean diameter of 10nm. A mechanism for the photocatalytic activity of nanocomposite was suggested and the degradation reaction obeyed the second-order kinetics. It was concluded that the degradation kinetics is changed due to the reduction of GO in the presence of blackberry juice.
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      PubDate: 2016-06-15T17:06:42Z
       
  • Analysis and structural characterization of pigments and materials used in
           Nicolae Grigorescu heritage paintings
    • Abstract: Publication date: 5 November 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 168
      Author(s): R.D. Rusu, B. Simionescu, A.V. Oancea, M. Geba, L. Stratulat, D. Salajan, L.E. Ursu, M.C. Popescu, M. Dobromir, M. Murariu, C. Cotofana, M. Olaru
      The combination of various mobile, non-invasive techniques (IR reflectography technique, optical microscopy, XRF, Raman and NIR spectroscopies) and lab-based devices (FTIR and XPS spectroscopies, SEM-EDX microscopy) lead to the first exhaustive investigation of pigments and materials used by the famous Romanian painter Nicolae Grigorescu in three cultural heritage paintings. The study of a large number of spots and samples allowed a rigorous analysis and a far-reaching insight into his work.
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      PubDate: 2016-06-15T17:06:42Z
       
  • Optical characteristics of the filamentary and diffuse modes in surface
           dielectric barrier discharge
    • Abstract: Publication date: 5 November 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 168
      Author(s): Ying Zhang, Jie Li, Nan Jiang, Ke-Feng Shang, Na Lu, Yan Wu
      Surface dielectric barrier discharge (DBD) plasmas generally exhibits filamentary and diffuse discharges at atmospheric air. The focus of this investigation is on the different optical characteristics and quantitative research about morphological features of two discharge modes. The temporally and spatially resolved characteristics of discharge phenomenon together with the gas temperature are presented with microsecond time scale. Discharge area is estimated by the sum of pixels that equal to “1” in MATLAB software. The formation of diffuse plasma mainly depends on an increase of the ionization coefficient and a creation of sufficient seed electrons by the Penning effect at low electric fields. Accordingly, experimental measurements show that diffuse discharge during the negative half cycle has good uniformity and stability compared with filamentary discharge during the positive half cycle. The rotational temperatures of plasma are determined by comparing the experimental spectra with the simulated spectra that have been investigated. The plasma gas temperature keeps almost constant in the filamentary discharge phase and subsequently increased by about 115K during the diffuse discharge. In addition, it is shown to be nearly identical in the axial direction. Non-uniform temperature distribution can be observed in the radial direction with large fluctuations. The plasma length is demonstrated almost the same between two discharge modes.
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      PubDate: 2016-06-15T17:06:42Z
       
  • New in situ generated acylhydrazidate-coordinated complexes and
           acylhydrazide molecules: Synthesis, structural characterization and
           photoluminescence property
    • Abstract: Publication date: 5 October 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 167
      Author(s): Yan-Ning Wang, Qi-Sheng Huo, Ping Zhang, Jie-Hui Yu, Ji-Qing Xu
      By utilizing the hydrothermal in situ acylation of organic acids with N2H4, three acylhydrazidate-coordinated compounds [Mn(L1)2(H2O)2] (L1=2,3-quinolinedicarboxylhydrazidate; HL1=2,3-dihydropyridazino[4,5-b] quinoline-1,4-dione) 1, [Mn2(ox)(L2)2(H2O)6]·2H2O (L2=benzimidazolate-5,6-dicarboxylhydrazide; HL2=6,7-dihydro-1H-imidazo[4,5-g]phthalazine-5,8-dione; ox=oxalate) 2, and [Cd(HL3)(bpy)] (L3=4,5-di(3′-carboxylphenyl)phthalhydrazidate; H3L3=6,7-dihydro-1H-imidazo[4,5-g]phthalazine-5,8-dione; bpy=2,2′-bipyridine) 3, as well as two acylhydrazide molecules L4 (L4=oxepino[2,3,4-de:7,6,5-d′e′]diphthalazine-4,10(5H,9H)-dione) 4 and L5 (L5=4,5-dibromophthalhydrazide; L5=6,7-dibromo-2,3-dihydrophthalazine-1,4-dione) 5 were obtained. X-ray single-crystal diffraction analysis reveals that (i) 1 only possesses a mononuclear structure, but it self-assembles into a 2-D supramolecular network via the Nhydrazine H⋯Nhydrazine and OwH⋯Ohydroxylimino interactions; (ii) 2 exhibits a dinuclear structure. Ox acts as the linker, while L2 just serves as a terminal ligand; (iii) In 3, L3 acts as a 3-connected node to propagate the 7-coordinated Cd2+ centers into a 1-D double-chain structure; (iv) 4 is a special acylhydrazide molecule. Two OH groups for the intermediates 3,3′-biphthalhydrazide further lose one water molecule to form 4; (v) 5 is a common monoacylhydrazide molecule. Via the Nhydrazine H⋯Ohydrazine, Ohydroxylimino H⋯Oacylamino and the π⋯π interactions, it self-assembles into a 2-D supramolecular network. The photoluminescence analysis reveals that 4 emits light with the maxima at 510nm.
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      PubDate: 2016-06-15T17:06:42Z
       
  • Co-dominant effect of selected natural dye sensitizers in DSSC performance
    • Abstract: Publication date: 5 October 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 167
      Author(s): Andery Lim, Piyasiri Ekanayake, Linda Biaw Leng Lim, J.M.R. Sarath Bandara

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      PubDate: 2016-06-15T17:06:42Z
       
  • Corrigendum to “Molecular geometry and vibrational studies of
           3,5-diamino-1,2,4-triazole using quantum chemical calculations and FT-IR
           and FT-RAMAN spectroscopies” [Spectrochim. Acta A Mol. Biomol.
           Spectrosc. 2011 Jan.; 78(1):347-53. doi: 10.1016/j.saa.2010.10.019. Epub
           2010 Oct. 26]
    • Abstract: Publication date: 5 October 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 167
      Author(s): L. Guennoun, J. El jastimi, F. Guédira, K. Marakchi, O.K. Kabbaj, A. El Hajji, S. Zaydoun



      PubDate: 2016-06-15T17:06:42Z
       
  • Biogenic terbium oxide nanoparticles as the vanguard against osteosarcoma
    • Abstract: Publication date: 5 November 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 168
      Author(s): Sana Iram, Salman Khan, Abu Ayoobul Ansary, Mohd Arshad, Sahabjada Siddiqui, Ejaz Ahmad, Rizwan H. Khan, Mohd Sajid Khan
      The synthesis of inner transition metal nanoparticles via an ecofriendly route is quite difficult. This study, for the first time, reports synthesis of terbium oxide nanoparticles using fungus, Fusarium oxysporum. The biocompatible terbium oxide nanoparticles (Tb2O3 NPs) were synthesized by incubating Tb4O7 with the biomass of fungus F. oxysporum. Multiple physical characterization techniques, such as UV-visible and photoluminescence spectroscopy, TEM, SAED, and zeta-potential were used to confirm the synthesis, purity, optical and surface characteristics, crystallinity, size, shape, distribution, and stability of the nanoemulsion of Tb2O3 NPs. The Tb2O3 NPs were found to inhibit the propagation of MG-63 and Saos-2 cell-lines (IC50 value of 0.102μg/mL) and remained non-toxic up to a concentration of 0.373μg/mL toward primary osteoblasts. Cell viability decreased in a concentration-dependent manner upon exposure to 10nm Tb2O3 NPs in the concentration range 0.023–0.373μg/mL. Cell toxicity was evaluated by observing changes in cell morphology, cell viability, oxidative stress parameters, and FACS analysis. Morphological examinations of cells revealed cell shrinkage, nuclear condensation, and formation of apoptotic bodies. The level of ROS within the cells—an indicator of oxidative stress was significantly increased. The induction of apoptosis at concentrations ≤IC50 was corroborated by 4′,6-diamidino-2-phenylindole dihydrochloride (DAPI) staining (DNA damage and nuclear fragmentation). Flow-cytometric studies indicated that the response was dose dependent with a threshold effect.
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      PubDate: 2016-06-15T17:06:42Z
       
  • Platycodin D induced apoptosis and autophagy in PC-12 cells through
           mitochondrial dysfunction pathway
    • Abstract: Publication date: 5 November 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 168
      Author(s): Chuan-Chuan Zeng, Cheng Zhang, Jun-Hua Yao, Shang-Hai Lai, Bing-Jie Han, Wei Li, Bing Tang, Dan Wan, Yun-Jun Liu
      In this article, the in vitro cytotoxicity of platycodin D was evaluated in human PC-12, SGC-7901, BEL-7402, HeLa and A549 cancer cell lines. PC-12 cells were sensitive to platycodin D treatment, with an IC50 value of 13.5±1.2μM. Morphological and comet assays showed that platycodin D effectively induced apoptosis in PC-12 cells. Platycodin D increased the levels of reactive oxygen species (ROS) and induced a decrease in mitochondrial membrane potential. Platycodin D induced cell cycle arrest at the G0/G1 phase in the PC-12 cell line. Platycodin D can induce autophagy. In addition, platycodin D can down-regulate the expression of Bcl-2 and Bcl-x, and up-regulate the levels of Bid protein in the PC-12 cells. The results demonstrated that platycodin D induced PC-12 cell apoptosis through a ROS-mediated mitochondrial dysfunction pathway.
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      PubDate: 2016-06-15T17:06:42Z
       
  • Synthesis, structural characterization, antimicrobial activities and
           theoretical investigations of some 4-(4-aminophenylsulfonyl) phenylimino)
           methyl)-4-(aryldiazenyl) phenol
    • Abstract: Publication date: 5 November 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 168
      Author(s): Motaleb Ghasemian, Ali Kakanejadifard, Tahereh Karami
      The azo-azomethine dyes with a different substitution have been designed from the reaction of 4,4′-diaminodiphenyl sulfone with 2-hydroxy-5-(aryldiazenyl)benzaldehyde. The compounds have been characterized by elemental analysis, Mass, IR, UV–Vis, TGA-DTA and NMR spectroscopy. The solvatochromism behaviors, effects of substitution and pH on the electronic absorption spectra of dyes were evaluated. The in vitro antimicrobial activities were also screened for their potential for antibiotic activities by broth micro dilution method. Also, the optimum molecular geometries, molecular electrostatic potential (MEP), nucleus-independent chemical shift (NICS) and frontier molecular orbitals (FMO), vibrational spectra (IR ) and electronic absorption (UV–Vis) spectra of the title compounds have been investigated with the help of DFT and TDDFT methods with 6-311++G(d,p) basis sets and PCM calculations. The results of the calculations show excellent agreement with the experimental value.
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      PubDate: 2016-06-15T17:06:42Z
       
  • Development and validation of simple spectrophotometric and chemometric
           methods for simultaneous determination of empagliflozin and metformin:
           Applied to recently approved pharmaceutical formulation
    • Abstract: Publication date: 5 November 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 168
      Author(s): Bassam M. Ayoub
      New univariate spectrophotometric method and multivariate chemometric approach were developed and compared for simultaneous determination of empagliflozin and metformin manipulating their zero order absorption spectra with application on their pharmaceutical preparation. Sample enrichment technique was used to increase concentration of empagliflozin after extraction from tablets to allow its simultaneous determination with metformin without prior separation. Validation parameters according to ICH guidelines were satisfactory over the concentration range of 2–12μgmL−1 for both drugs using simultaneous equation with LOD values equal to 0.20μgmL−1 and 0.19μgmL−1, LOQ values equal to 0.59μgmL−1 and 0.58μgmL−1 for empagliflozin and metformin, respectively. While the optimum results for the chemometric approach using partial least squares method (PLS-2) were obtained using concentration range of 2–10μgmL−1. The optimized validated methods are suitable for quality control laboratories enable fast and economic determination of the recently approved pharmaceutical combination Synjardy® tablets.
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      PubDate: 2016-06-15T17:06:42Z
       
  • Inhibitory mechanisms of glabridin on tyrosinase
    • Abstract: Publication date: 5 November 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 168
      Author(s): Jianmin Chen, Xiaojing Yu, Yufeng Huang
      Tyrosinase is an oxidase that is the rate-limiting enzyme for controlling the production of melanin in the human body. Overproduction of melanin could lead to a variety of skin disorders. Glabridin, an isoflavan, isolated from the root of Glycyrrhiza glabra Linn, has exhibited several pharmacological activities, including excellent inhibitory effects on tyrosinase. In this paper, the inhibitory kinetics of glabridin on tyrosinase and their binding mechanisms were determined using spectroscopic, zebrafish model and molecular docking techniques. The results indicate that glabridin reversibly inhibits tyrosinase in a noncompetitive manner through a multiphase kinetic process with the IC50 of 0.43μmol/L. It has been shown that glabridin had a strong ability to quench the intrinsic fluorescence of tyrosinase mainly through a static quenching procedure, suggesting a stable glabridin-tyrosinase complex may be generated. The results of molecular docking suggest that glabridin did not directly bind to the active site of tyrosinase. Moreover, according to the results of zebrafish model system, glabridin shows no effects on melanin synthesis in zebrafish but presents toxicity to zebrafish embryo. The possible inhibitory mechanisms, which will help to design and search for tyrosinase inhibitors especially for glabridin analogues, were proposed.
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      PubDate: 2016-06-15T17:06:42Z
       
  • Enhancing prediction power of chemometric models through manipulation of
           the fed spectrophotometric data: A comparative study
    • Abstract: Publication date: 5 October 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 167
      Author(s): Ahmed S. Saad, Abdallah M. Hamdy, Fathy M. Salama, Mohamed Abdelkawy
      Effect of data manipulation in preprocessing step proceeding construction of chemometric models was assessed. The same set of UV spectral data was used for construction of PLS and PCR models directly and after mathematically manipulation as per well known first and second derivatives of the absorption spectra, ratio spectra and first and second derivatives of the ratio spectra spectrophotometric methods, meanwhile the optimal working wavelength ranges were carefully selected for each model and the models were constructed. Unexpectedly, number of latent variables used for models' construction varied among the different methods. The prediction power of the different models was compared using a validation set of 8 mixtures prepared as per the multilevel multifactor design and results were statistically compared using two-way ANOVA test. Root mean squares error of prediction (RMSEP) was used for further comparison of the predictability among different constructed models. Although no significant difference was found between results obtained using Partial Least Squares (PLS) and Principal Component Regression (PCR) models, however, discrepancies among results was found to be attributed to the variation in the discrimination power of adopted spectrophotometric methods on spectral data.
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      PubDate: 2016-06-15T17:06:42Z
       
  • In-situ formation of ion-association nanoparticles induced enhancements of
           resonance Rayleigh scattering intensities for quantitative analysis of
           trace Hg2+ ions in environmental samples
    • Abstract: Publication date: 5 October 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 167
      Author(s): Qingling Yang, Jian Liu, Banglin Li, Xiaoli Hu, Shaopu Liu, Gangcai Chen
      In this paper, Hg2+ ions are demonstrated to form anionic [HgI4]2− complexes after interacting with massive amount of I− ions. Subsequently, the addition of tetradecyl pyridyl bromide (TPB) can make [HgI4]2− anionic complexes react with univalent tetradecyl pyridyl cationic ions (TP+), forming dispersed ion-association complexes (TP)2(HgI4). Due to the extrusion action of water and Van der Waals force, the hydrophobic ion-association complexes aggregate together, forming dispersed nanoparticles with an average size of about 8.5nm. Meanwhile, resonance Rayleigh scattering (RRS) intensity is apparently enhanced due to the formation of (TP)2(HgI4) ion-association nanoparticles, contributing to a novel technique for Hg2+ detection. The wavelength of 365nm is chosen as a detection wavelength and several conditions affecting the RRS responses of Hg2+ are optimized. Under the optimum condition, the developed method is used for the determination of Hg2+ in aqueous solution and the detection limit is estimated to be 0.8ngmL−1. Finally, the practical application of the developed method can be confirmed through the detections of Hg2+ in waste and river water samples with satisfactory results.
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      PubDate: 2016-06-15T17:06:42Z
       
  • Fluorescence in complexes based on quinolines-derivatives: a search for
           better fluorescent probes
    • Abstract: Publication date: 5 November 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 168
      Author(s): Carolina Z.P. Mecca, Fernando L.A. Fonseca, Izilda A. Bagatin
      Quinoline-derived fluorescent complexes were designed; synthesized by the reaction of 5-nitro-8-hydroxyquinoline and 5-chloro-8-hydroxyquinoline with Al3+, Mg2+, Zn2+, and Cd2+ salts (1–8); and characterized. The 1H NMR spectra of complexes 1 and 5, containing Al3+, were consistent with an octahedral structure having approximate D3 symmetry, and the results supported the favored facial isomer (fac). Data for complexes 2–4 and 6–8 supported the formation of tetrahedral structures. Intense luminescence was detected for complexes 5–8, even with the naked eye, as indicated by quantum yield values of 0.087, 0.094, 0.051, and 0.021, respectively. Furthermore, in contrast to 5-nitro-8-hydroxyquinoline, the 5-chloro-8-hydroxyquinoline ligand exhibited bands at different energies depending on the coordinated metal, which supported its potential application in ionic and biological probes, as well as in cell imaging.
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      PubDate: 2016-06-15T17:06:42Z
       
  • Dispersion analysis with inverse dielectric function modelling
    • Abstract: Publication date: 5 November 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 168
      Author(s): Thomas G. Mayerhöfer, Vladimir Ivanovski, Jürgen Popp
      We investigate how dispersion analysis can profit from the use of a Lorentz-type description of the inverse dielectric function. In particular at higher angles of incidence, reflectance spectra using p-polarized light are dominated by bands from modes that have their transition moments perpendicular to the surface. Accordingly, the spectra increasingly resemble inverse dielectric functions. A corresponding description can therefore eliminate the complex dependencies of the dispersion parameters, allow their determination and facilitate a more accurate description of the optical properties of single crystals.
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      PubDate: 2016-06-15T17:06:42Z
       
  • Naphthol-based fluorescent sensors for aluminium ion and application to
           bioimaging
    • Abstract: Publication date: 5 November 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 168
      Author(s): Bin Liu, Pan-feng Wang, Jie Chai, Xiang-quan Hu, Tingting Gao, Jian-bin Chao, Ting-gui Chen, Bin-sheng Yang
      Three naphthol Schiff base-type fluorescent sensors, 1,3-Bis(2-hydroxy-1-naphthylideneamino)propane (L1), 1,3-Bis(1-naphthylideneamino)-2-hydroxypropane (L2) and 1,3-Bis(2-hydroxy-1-naphthylideneamino)-2-hydroxypropane (L3), have been synthesized. Their recognition abilities for Al3+ are studied by fluorescence spectra. Coordination with Al3+ inhibited the CN isomerization of Schiff base which intensely increase the fluorescence of L1–L3. Possessing a suitable space coordination structure, L3 is a best selective probe for Al3+ over other metal ions in MeOH–HEPES buffer (3/7, V/V, pH=6.6, 25°C, λem =435nm). A turn-on ratio over 140-fold is triggered with the addition of 1.0 equiv. Al3+ to L3. The binding constant K a of L3-Al3+ is found to be 1.01×106.5 M−1 in a 1:1 complex mode. The detection limit for Al3+ is 0.05μM. Theoretical calculations have also been included in support of the configuration of the L3-Al3+ complex. Importantly, the probe L3 has been successfully used for fluorescence imaging in colon cancer SW480 cells.
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      PubDate: 2016-06-15T17:06:42Z
       
  • Spectral and chemical characterization of jarosite in a palaeolacustrine
           depositional environment in Warkalli Formation in Kerala, South India and
           its implications
    • Abstract: Publication date: 5 November 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 168
      Author(s): Mahima Singh, V.J. Rajesh, K.S. Sajinkumar, K. Sajeev, S.N. Kumar
      Coastal cliffs fringing the Arabian Sea near Varkala exhibits the Warkalli Formation of the Tertiary sequence of Kerala, South India, with well-marked occurrence of jarosite associated with other hydrous mineral phases of phyllosilicate family in a palaeo-lacustrine depositional environment. Sandy phyllosilicates dominate the mineral assemblage, but jarosite occurs as a prominent secondary phase formed during acid-sulphate alteration of iron sulphide in this area. Here, we discuss about the potentiality of spectroscopic techniques to identify the possible mineral phases in the collected samples. The samples from the coastal cliffs have been characterized by hyperspectral analysis (VIS-NIR-SWIR), X-ray Diffraction (XRD), Fourier Transform Infra-red Reflectance (FTIR), Electron Probe Microanalysis (EPMA) and Laser Raman spectroscopy. The spectral and chemical analyses have confirmed the jarosite as natrojarosite and phyllosilicate as kaolinite. Other accessory phases have also been identified through XRD. FTIR spectroscopy has played a major role in identifying the major hydrous bonds between the minerals. VIS-NIR-SWIR spectra show several optimum spectral features at 910nm, 1470nm, 1849–1864nm (in the form of a doublet), 1940nm and 2270nm, which could be utilised to locate jarosite in the remotely-sensed data. X-ray diffraction peaks helped in the identification of maximum number of minerals (kaolinite, smectite, quartz, feldspar, pyrite, marcasite and hematite) and the variation in jarosite content in the samples. We propose the formation of jarosite in the region by a seasonal, local and temporary development of acidic conditions. Abundance of organic matter in a fluvio-lacustrine environment has developed anaerobic conditions by removing available oxygen through decomposition of organic matter containing sulphur compounds. The sulphur thus liberated combines with hydrogen from water to develop acidic conditions and resulted in the formation of jarosite. The occurrence of jarosite in Warkalli Formation suggests on and off supply of water during diagenesis. Jarosite has been detected as a prominent deposit in several regions on Mars by Mars Exploration rover Opportunity and Mars Reconnaissance Orbiter-Compact Reconnaissance Imaging Spectrometer for Mars (CRISM). This study of jarosite formation in terrestrial environment will influence our understanding on the mineral precipitation, diagenesis and hydration processes on Mars. Additionally, it also shows the importance of spectroscopic techniques like Raman spectrometry to be used in future missions to Mars to further validate the results of orbital spectroscopy.
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      PubDate: 2016-06-15T17:06:42Z
       
  • A novel colorimetric and turn-on fluorescent chemosensor for iron(III) ion
           detection and its application to cellular imaging
    • Abstract: Publication date: 5 November 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 168
      Author(s): Aoheng Luo, Hongqing Wang, Yuyuan Wang, Qiao Huang, Qin Zhang
      A novel rhodamine-based dual probe Rh-2 for trivalent ferric ions (Fe3+) was successfully designed and synthesized, which exhibited a highly sensitive and selective recognition towards Fe3+ with an enhanced fluorescence emission in methanol-water media (v/v=7/3, pH=7.2). The probe Rh-2 could be applied to the determination of Fe3+ with a linear range covering from 3.0×10−7 to 1.4×10−5 M and a detection limit of 1.24×10−8 M. Meanwhile, the binding ratio of Rh-2 and Fe3+ was found to be 1:1. Most importantly, the fluorescence and color signal changes of the Rh-2 solution were specific to Fe3+ over other commonly coexistent metal ions. Moreover, the probe Rh-2 has been used to image Fe3+ in living cells with satisfying results.
      Graphical abstract image

      PubDate: 2016-06-15T17:06:42Z
       
  • Vibrationally high-resolved electronic spectra of MCl2 (M=C, Si, Ge, Sn,
           Pb) and photoelectron spectra of MCl2−
    • Abstract: Publication date: 5 October 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 167
      Author(s): Yibin Ran, Min Pang, Wei Shen, Ming Li, Rongxing He
      We systematically studied the vibrational-resolved electronic spectra of group IV dichlorides using the Franck–Condon approximation combined with the Duschinsky and Herzberg–Teller effects in harmonic and anharmonic frameworks (only the simulation of absorption spectra includes the anharmonicity). Calculated results showed that the band shapes of simulated spectra are in accordance with those of the corresponding experimental or theoretical ones. We found that the symmetric bend mode in progression of absorption is the most active one, whereas the main contributor in photoelectron spectra is the symmetric stretching mode. Moreover, the Duschinsky and anharmonic effects exert weak influence on the absorption spectra, except for PbCl2 molecule. The theoretical insights presented in this work are significant in understanding the photophysical properties of MCl2 (M=C, Si, Ge, Sn, Pb) and studying the Herzberg–Teller and the anharmonic effects on the absorption spectra of new dichlorides of this main group.
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      PubDate: 2016-06-15T17:06:42Z
       
  • A novel strategy for spectrophotometric simultaneous determination of
           amitriptyline and nortriptyline based on derivation with a quinonoid
           compound in serum samples
    • Abstract: Publication date: 5 November 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 168
      Author(s): Amir Farnoudian-Habibi, Bakhshali Massoumi, Mehdi Jaymand

      Graphical abstract image

      PubDate: 2016-06-15T17:06:42Z
       
  • Spectroscopic analyses of soil samples outside Nile Delta of Egypt
    • Abstract: Publication date: 5 November 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 168
      Author(s): Ahmed Fakhry, Osama Osman, Hend Ezzat, Medhat Ibrahim
      Soil in Egypt, especially around Delta is exposed to various pollutants which are affecting adversely soil fertility and stability. Humic Acids (HA) as a main part of soil organic matter (SOM) represent the heart of the interaction process of inorganic pollutants with soil. Consequently, Fourier transform infrared spectroscopy (FTIR) and Nuclear magnetic resonances (NMR) were used to characterize soil, sediment and extracted HA. Resulting data confirmed that the HA was responsible for transporting inorganic pollutants from surface to subsurface reaching the ground water, which may represent a high risk on public health. The transport process is coming as carboxyl in surface soil changed into metal carboxylate then transferred into the carboxyl in bottom soil.
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      PubDate: 2016-06-15T17:06:42Z
       
  • A new spectrophotometric method for determination of EDTA in water using
           its complex with Mn(III)
    • Abstract: Publication date: 5 November 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 168
      Author(s): Carlos Eduardo O. Andrade, André F. Oliveira, Antônio A. Neves, Maria Eliana L.R. Queiroz
      EDTA is an important ligand used in many industrial products as well as in agriculture, where it is employed to assist in phytoextraction procedures and the absorption of nutrients by plants. Due to its intensive use and recalcitrance, it is now considered an emerging pollutant in water, so there is great interest in techniques suitable for its monitoring. This work proposes a method based on formation of the Mn(III)-EDTA complex after oxidation of the Mn(II)-EDTA complex by PbO2 immobilized on cyanoacrylate spheres. A design of experiments (DOE) based on the Doehlert matrix was used to determine the optimum conditions of the method, and the influence of the variables was evaluated using a multiple linear regression (MLR) model. The optimized method presented a linear response in the range from 0.77 to 100.0μmolL−1, with analytical sensitivity of 7.7×103 Lmol−1, a coefficient of determination of 0.999, and a limit of detection of 0.23μmolL−1. The method was applied using samples fortified at different concentration levels, and the recoveries achieved were between 97.0 and 104.9%.
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      PubDate: 2016-06-15T17:06:42Z
       
  • Resonance Rayleigh scattering method for highly sensitive detection of
           chitosan using aniline blue as probe
    • Abstract: Publication date: 5 November 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 168
      Author(s): Weiai Zhang, Caijuan Ma, Zhengquan Su, Yan Bai
      This paper describes a highly sensitive and accurate approach using aniline blue (AB) (water soluble) as a probe to determine chitosan (CTS) through Resonance Rayleigh scattering (RRS). Under optimum experimental conditions, the intensities of RRS were linearly proportional to the concentration of CTS in the range from 0.01 to 3.5μg/mL, and the limit of detection (LOD) was 6.94ng/mL. Therefore, a new and highly sensitive method based on RRS for the determination of CTS has been developed. Furthermore, the effect of molecular weight of CTS and the effect of the degree of deacetylation of CTS on the accurate quantification of CTS was studied. The experimental data was analyzed by linear regression analysis, which indicated that the molecular weight and the degree of deacetylation of CTS had no statistical significance and this method could be used to determine CTS accurately. Meanwhile, this assay was applied for CTS determination in health products with satisfactory results.
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      PubDate: 2016-06-15T17:06:42Z
       
  • Theoretical study of optical activity of 1:1 hydrogen bond complexes of
           water with S-warfarin
    • Abstract: Publication date: 5 November 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 168
      Author(s): Mehrdad Dadsetani, Ahmad Abdolmaleki, Abedin Zabardasti
      The molecular interaction between S-warfarin (SW) and a single water molecule was investigated using the B3LYP method at 6-311++G(d,p) basis set. The vibrational spectra of the optimized complexes have been investigated for stabilization checking. Quantum theories of atoms in molecules, natural bond orbitals, molecular electrostatic potentials and energy decomposition analysis methods have been applied to analyze the intermolecular interactions. The intermolecular charge transfer in the most stable complex is in the opposite direction from those in the other complexes. The optical spectra and the hyperpolarizabilities of SW-water hydrogen bond complexes have been computed.
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      PubDate: 2016-06-15T17:06:42Z
       
  • Application of electrochemical impedance spectroscopy: A phase behavior
           study of babassu biodiesel-based microemulsions
    • Abstract: Publication date: 5 November 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 168
      Author(s): Thulio C. Pereira, Carlos A.F. Conceição, Alamgir Khan, Raquel M.T. Fernandes, Maira S. Ferreira, Edmar P. Marques, Aldaléa L.B. Marques
      Microemulsions are thermodynamically stable systems of two immiscible liquids, one aqueous and the other of organic nature, with a surfactant and/or co-surfactant adsorbed in the interface between the two phases. Biodiesel-based microemulsions, consisting of alkyl esters of fatty acids, open a new means of analysis for the application of electroanalytical techniques, and is advantageous as it eliminates the required pre-treatment of a sample. In this work, the phase behaviours of biodiesel-based microemulsions were investigated through the electrochemical impedance spectroscopy (EIS) technique. We observed thatan increase in the amount of biodiesel in the microemulsion formulation increases the resistance to charge transfer at the interface. Also, the electrical conductivity measurements revealed that a decrease or increase in electrical properties depends on the amount of biodiesel. EIS studies of the biodiesel-based microemulsion samples showed the presence of two capacitive arcs: one high-frequency and the other low-frequency. Thus, the formulation of microemulsions plays an important role in estimating the electrical properties through the electrochemical impedance spectroscopy technique.
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      PubDate: 2016-06-15T17:06:42Z
       
  • Corynebacterium glutamicum MTCC 2745 immobilized on granular activated
           carbon/MnFe2O4 composite: A novel biosorbent for removal of As(III) and
           As(V) ions
    • Abstract: Publication date: 5 November 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 168
      Author(s): M.S. Podder, C.B. Majumder
      The optimization of biosorption/bioaccumulation process of both As(III) and As(V) has been investigated by using the biosorbent; biofilm of Corynebacterium glutamicum MTCC 2745 supported on granular activated carbon/MnFe2O4 composite (MGAC). The presence of functional groups on the cell wall surface of the biomass that may interact with the metal ions was proved by FT–IR. To determine the most appropriate correlation for the equilibrium curves employing the procedure of the non-linear regression for curve fitting analysis, isotherm studies were performed for As(III) and As(V) using 30 isotherm models. The pattern of biosorption/bioaccumulation fitted well with Vieth–Sladek isotherm model for As(III) and Brouers–Sotolongo and Fritz–Schlunder–V isotherm models for As(V). The maximum biosorption/bioaccumulation capacity estimated using Langmuir model were 2584.668mg/g for As(III) and 2651.675mg/g for As(V) at 30°C temperature and 220min contact time. The results showed that As(III) and As(V) removal was strongly pH–dependent with an optimum pH value of 7.0. D–R isotherm studies specified that ion exchange might play a prominent role.
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      PubDate: 2016-06-15T17:06:42Z
       
  • Using FTIR-photoacoustic spectroscopy for phosphorus speciation analysis
           of biochars
    • Abstract: Publication date: 5 November 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 168
      Author(s): Georgios Bekiaris, Clément Peltre, Lars S. Jensen, Sander Bruun
      In the last decade, numerous studies have evaluated the benefits of biochar for improving soil quality. The purposes of the current study were to use Fourier transform infrared-photoacoustic spectroscopy (FTIR-PAS) to analyse P species in biochar and to determine the effect of pyrolysis temperature on P speciation. The photoacoustic detector has a range of advantages for the very dark biochar samples in comparison to more traditional reflectance or transmission FTIR detectors. The spectra turned out to be more informative in the regions with P vibrations for biochar produced at temperatures above 400°C, where most of the remaining organic compounds were aromatic and therefore not overlapping with the P vibrations. For biochars produced from the solid fraction of digestate from biogas production, an increase in the pyrolysis temperature led to the formation of a large variety of P species. Hydroxylapatite and tricalcium phosphate were the most dominant P species in the mid to high temperature range (600–900°C), while at 1050°C apatite, iron phosphates, variscite and calcium phosphates were identified. However, the changes in P speciation in biochars produced from bone meal at different temperatures were smaller than in the biochars from digestate. Hydroxylapatite and calcium phosphates were identified in biochar produced at all temperatures, while there was some indication of struvite formation.
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      PubDate: 2016-06-15T17:06:42Z
       
  • Discovering “The Italian Flag” by Fernando Melani
           (1907–1985)
    • Abstract: Publication date: 5 November 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 168
      Author(s): Serena Carlesi, Giovanni Bartolozzi, Costanza Cucci, Veronica Marchiafava, Marcello Picollo, Jacopo La Nasa, Francesca Di Girolamo, Marialaura Dilillo, Francesca Modugno, Ilaria Degano, Maria Perla Colombini, Stefano Legnaioli, Giulia Lorenzetti, Vincenzo Palleschi
      In the occasion of the celebrations for the 150th anniversary of the founding of Italy (1861–2011), it was decided to analyse the artwork “The Italian Flag” (La Bandiera Italiana) created by the artist Fernando Melani (Pistoia, 1907–1985), one of the precursors of the Poor Art artistic movement in Italy. This project is a follow-up to a previous study which was mainly focused on the pigments and dyes found in his home-studio. The main goal of this paper is to identify a correct diagnostic plan, based on the use of a combination of non-invasive and micro-invasive methodologies, in order to determine the state of preservation and define the best conservation procedures for a contemporary artwork. Visible, infrared and infrared false colour images as well as the Fibre Optic Reflectance Spectroscopy (FORS) technique were applied in situ to analyse The Italian Flag. Laser Induced Breakdown Spectroscopy (LIBS), Fourier Transform Infrared (FT-IR) and micro-Raman spectroscopies, Pyrolysis-Gas Chromatography/Mass Spectroscopy (Py-GC/MS), High Performance Liquid Chromatography with Diode Arrays Detection (HPLC-DAD) and Mass Spectrometric Detection (HPLC-ESI-Q-ToF) were all applied to three small samples detached from the three painted (green-blue, white and red-yellow, respectively) areas of the flag. The combination of the data obtained with all these techniques made possible a comprehensive understanding of both the chemical composition and physical behaviour of the materials used by the artist and supported curators in defining the preventive conservation of this artwork.
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      PubDate: 2016-06-15T17:06:42Z
       
  • Spectrometric measurements and DFT studies on new complex of copper (II)
           with
           
    • Abstract: Publication date: 5 November 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 168
      Author(s): Haoyang Zhang, Jie Hu, Jianying Zhao, Yu Zhang
      The molecular structure of a new complex of copper (II) with (E)-9-ethyl-3-(2-(6-(4-methylpyridin-2-yl)pyridin-3-yl)vinyl)-9H-carbazole ([Cu2(emppc)2Cl2]Cl2) was optimized with B3LYP/LanL2DZ, PBE1PBE/LanL2DZ and M062X/LanL2DZ theoretical level. The ligand, (E)-9-ethyl-3-(2-(6-(4-methylpyridin-2-yl)pyridin-3-yl)vinyl)-9H-carbazole (emppc), binds to Cu(II) ions with a bi-dentate mode, two Cl− serve as bridging ligand, each Cu(II) ion has a highly distorted tetrahedron coordination geometry. With M062X/LanL2DZ theoretical level, the calculated interaction energies of Cu(II) with coordination atoms N are between 183.3–200.0kJmol−1 for α spin and 319.4–324.9kJmol−1 for β spin, and interaction energies of Cu(II) with coordination atoms Cl atom are 248.0–252.4kJmol−1 for α spin and 332.6–333.6kJmol−1 for β spin. The experimental Fourier transform infrared spectrum was assigned. The calculated IR based on B3LYP/LanL2DZ, PBE1PBE/LanL2DZ and M062X/LanL2DZ methods were performed and compared with experimental results. The UV–Vis experimental spectra of [Cu2(emppc)2Cl2]Cl2 was measured in methanol solution. The calculated electronic spectrum was performed with TD/M062X and PCM-TD/M062X methods with LanL2DZ basis set. The nature bond orbital analysis and temperature dependence of the thermodynamic properties were calculated with the same methods.
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      PubDate: 2016-06-15T17:06:42Z
       
  • Theoretical and experimental studies of the stability of drug-drug
           interact
    • Abstract: Publication date: 5 November 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 168
      Author(s): Monica F.R. Soares, Lariza D.S. Alves, Daniela Nadvorny, José L. Soares-Sobrinho, Pedro J. Rolim-Neto
      Several factors can intervene in the molecular properties and consequently in the stability of drugs. The molecular complexes formation often occur due to favor the formation of hydrogen bonds, leading the system to configuration more energy stable. This work we aim to investigate through theoretical and experimental methods the relation between stability and properties of molecular complexes the molecular complex formed between the drugs, efavirenz (EFV), lamivudine (3TC) and zidovudine (AZT). With this study was possible determining the most stable complex formed between the compounds evaluated. In addition the energy and structural properties of the complex formed in relation to its individual components allowed us to evaluate the stability of the same.
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      PubDate: 2016-06-15T17:06:42Z
       
  • Off–On–Off fluorescence behavior of an intramolecular charge
           transfer probe toward anions and CO2
    • Abstract: Publication date: 5 November 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 168
      Author(s): Rashid Ali, Syed S. Razi, Mohammad Shahid, Priyanka Srivastava, Arvind Misra
      The photophysical behavior of a newly developed fluorescent probe, tricyanoethylphenyl phenanthroimidazole (TCPPI) has been studied. Upon interaction of different class of anions TCPPI displayed naked–eye sensitive fluorescence “turn–on” response to detect selectively F− (0.98μM, 18.62ppb) and CN− (1.12μM, 29.12ppb) anions in acetonitrile (MeCN). Job's plot analysis revealed a 1:1 binding stoichiometry between probe and anions. The spectral data analysis and 1H NMR titration studies suggested about the affinity of F− and CN− anions with moderately acidic −NH fragment of imidazolyl unit of probe through deprotonation and H-bonding interaction. Moreover, the anion activated probe upon interaction with CO2 revived photophysical properties of probe, “On-Off-On” type fluorescence and enabled anion-induced CO2 sensing in the medium.
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      PubDate: 2016-06-15T17:06:42Z
       
  • Vibrational, XRD and 13C NMR studies of DL-phenylglycinium
           methanesulfonate crystal
    • Abstract: Publication date: 5 November 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 168
      Author(s): Łukasz Wołoszyn, Marek Ilczyszyn, Maria M. Ilczyszyn, Karolina Haupa
      A new crystal formed by DL-phenylglycine and methanesulfonic acid (PGLYMS) was obtained and studied by X-ray diffraction, IR and Raman spectroscopy, solid state NMR and DSC methods. Additionally, theoretical computations for the phenylglycine cation were carried out (DFT/B3LYP/aug-cc-pVDZ). Our results show that PGLYMS does not exhibit any phase transitions and crystallizes in the P21/c space group of monoclinic system (Z =4). Detailed analysis of its structure and its IR, Raman and NMR spectra is presented.
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      PubDate: 2016-06-15T17:06:42Z
       
  • Accurate multireference configuration interaction calculations of the 24
           Λ-S states and 60 Ω states of the BO+ cation
    • Abstract: Publication date: 5 November 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 168
      Author(s): Hui Liu, Deheng Shi, Jinfeng Sun, Zunlue Zhu
      The potential energy curves were calculated for the 24 Λ-S states correlating with the lowest four dissociation channels of the BO+ cation. The potential energy curves were also computed for the 60 Ω states generated from the 24 Λ-S states. Calculations were made for internuclear separations from 0.08 to 1.05nm using the CASSCF method, which was followed by the icMRCI approach with the correlation-consistent basis sets. Core–valence correlation, scalar relativistic and basis extrapolation were accounted for. Of the 24 Λ-S states, only three states (25Π, 15Σ−, and 25Σ−) were found to be repulsive; only the 15Δ state was found to be a very weakly-bound state; and the E1Π, 23Π, and 15Π states were found to be very strong bound. In addition, the B1Σ+ and 31Σ+ states have double wells by the avoided crossing between the two states. The a3Π, 13Σ−, and 23Σ− states are inverted with the spin–orbit coupling effect included. The spectroscopic parameters were determined and the vibrational properties of several Λ-S states were predicted. Comparison with available experimental data shows that the methodology employed is highly accurate for this system.
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      PubDate: 2016-06-15T17:06:42Z
       
  • Quenching of chlorophyll fluorescence induced by silver nanoparticles
    • Abstract: Publication date: 5 November 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 168
      Author(s): A.M. Queiroz, A.V. Mezacasa, D.E. Graciano, W.F. Falco, J.-C. M'Peko, F.E.G. Guimarães, T. Lawson, I. Colbeck, S.L. Oliveira, A.R.L. Caires
      The interaction between chlorophyll (Chl) and silver nanoparticles (AgNPs) was evaluated by analyzing the optical behavior of Chl molecules surrounded by different concentrations of AgNPs (10, 60, and 100nm of diameter). UV–Vis absorption, steady state and time-resolved fluorescence measurements were performed for Chl in the presence and absence of these nanoparticles. AgNPs strongly suppressed the Chl fluorescence intensity at 678nm. The Stern-Volmer constant (KSV) showed that fluorescence suppression is driven by the dynamic quenching process. In particular, KSV was nanoparticle size-dependent with an exponential decrease as a function of the nanoparticle diameter. Finally, changes in the Chl fluorescence lifetime in the presence of nanoparticles demonstrated that the fluorescence quenching may be induced by the excited electron transfer from the Chl molecules to the metal nanoparticles.
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      PubDate: 2016-06-15T17:06:42Z
       
  • Modelling mercury accumulation in minerogenic peat combining FTIR-ATR
           spectroscopy and partial least squares (PLS)
    • Abstract: Publication date: 5 November 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 168
      Author(s): Marta Pérez-Rodríguez, Ingrid Horák-Terra, Luis Rodríguez-Lado, Antonio Martínez Cortizas



      PubDate: 2016-06-15T17:06:42Z
       
  • A novel fluorescent probe for rapid and sensitive detection of hydrogen
           sulfide in living cells
    • Abstract: Publication date: 5 November 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 168
      Author(s): Jian Pan, Junchao Xu, Youlai Zhang, Liang Wang, Caiqin Qin, Lintao Zeng, Yue Zhang
      A novel fluorescent probe for H2S was developed based on a far-red emitting indole-BODIPY, which was decorated with morpholine and 2,4-dinitrobenzenesulfonyl (DNBS) group. This probe showed rapid response (t1/2 =3min), high selectivity and sensitivity for H2S with significant colorimetric and fluorescence OFF–ON signals, which was triggered by cleavage of 2,4-dinitrobenzenesulfonyl group. This probe could quantitatively detect the concentrations of H2S ranging from 0 to 60μM, and the detection of limit was found to be as low as 26nM. Cell imaging results indicated that the probe could detect and visualize H2S in the living cells.
      Graphical abstract image

      PubDate: 2016-06-15T17:06:42Z
       
  • Photo-induced interaction of thioglycolic acid (TGA)-capped CdTe quantum
           dots with cyanine dyes
    • Abstract: Publication date: 5 November 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 168
      Author(s): Mostafa F. Abdelbar, Tarek A. Fayed, Talaat M. Meaz, El- Zeiny M. Ebeid
      The photo-induced interaction of three different sizes of thioglycolic acid (TGA)-capped CdTe quantum dots (CdTe QDs) with two monomethine cyanine dyes belonging to the thiazole orange (TO) family has been studied. Positively charged cyanines interact with QDs surface which is negatively charged due to capping agent carboxylate ions. The energy transfer parameters including Stern-Volmer constant, Ksv, number of binding sites, n, quenching sphere radius, r, the critical energy transfer distance, R0, and energy transfer efficiencies, E have been calculated. The effect of structure and the number of aggregating molecules have been studied as a function of CdTe QDs particle size. Combining organic and inorganic semiconductors leads to increase of the effective absorption cross section of the QDs which can be utilized in novel nanoscale designs for light-emitting, photovoltaic and sensor applications. A synthesized triplet emission of the studied dyes was observed using CdTe QDs as donors and this is expected to play a potential role in molecular oxygen sensitization and in photodynamic therapy (PDT) applications.
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      PubDate: 2016-06-15T17:06:42Z
       
  • Analysis of binding ability of two tetramethylpyridylporphyrins to albumin
           and its complex with bilirubin
    • Abstract: Publication date: 5 November 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 168
      Author(s): Alexey V. Solomonov, Maria K. Shipitsyna, Arthur S. Vashurin, Evgeniy V. Rumyantsev, Alexander S. Timin, Sergey P. Ivanov
      An interaction between 5,10,15,20-tetrakis-(N-methyl-x-pyridyl)porphyrins, x =2; 4 (TMPyPs) with bovine serum albumin (BSA) and its bilirubin (BR) complex was investigated by UV–Viz and fluorescence spectroscopy under imitated physiological conditions involving molecular docking studies. The parameters of forming intermolecular complexes (binding constants, quenching rate constants, quenching sphere radius etc.) were determined. It was showed that the interaction between proteins and TMPyPs occurs via static quenching of protein fluorescence and has predominantly hydrophobic and electrostatic character. It was revealed that obtained complexes are relatively stable, but in the case of TMPyP4 binding with proteins occurs better than TMPyP2. Nevertheless, both TMPyPs have better binding ability with free protein compared to BRBSA at the same time. The influence of TMPyPs on the conformational changes in protein molecules was studied using synchronous fluorescence spectroscopy. It was found that there is no competition of BR with TMPyPs for binging sites on protein molecule and BR displacement does not occur. Molecular docking calculations have showed that TMPyPs can bind with albumin via tryptophan residue in the hydrophilic binding site of protein molecule but it is not one possible interaction way.
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      PubDate: 2016-06-15T17:06:42Z
       
  • Fluorescence characteristics of carbon nanoemitters derived from sucrose
           by green hydrothermal and microwave methods
    • Abstract: Publication date: 5 December 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 169
      Author(s): Rajesh Patidar, Babulal Rebary, Gopala Ram Bhadu
      In this work, fluorescent carbon nanoparticles (CNPs) were prepared through two green methods i.e. microwave and hydrothermal, using sucrose as carbon precursor. Both of these methods have offered fluorescent CNPs as characterized by TEM, FTIR, zeta potential, absorbance and emission techniques. Excitation dependent emission spectra were exhibited by aqueous dispersion of these CNPs when they were subjected to different excitation wavelengths. The luminous characteristics of CNPs obtained from both of these methods were studied and compared. Their fluorescence stability in water and buffer was monitored for about three months. Influence of pH and various metal ions on emission spectra were investigated.
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      PubDate: 2016-06-15T17:06:42Z
       
  • Room temperature fluorescence and phosphorescence study on the
           interactions of iodide ions with single tryptophan containing serum
           albumins
    • Abstract: Publication date: 5 December 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 169
      Author(s): Krystian Gałęcki, Agnieszka Kowalska-Baron
      In this study, the influence of heavy-atom perturbation, induced by the addition of iodide ions, on the fluorescence and phosphorescence decay parameters of some single tryptophan containing serum albumins isolated from: human (HSA), equine (ESA) and leporine (LSA) has been studied. The obtained results indicated that, there exist two distinct conformations of the proteins with different exposure to the quencher. In addition, the Stern–Volmer plots indicated saturation of iodide ions in the binding region. Therefore, to determine quenching parameter, we proposed alternative quenching model and we have performed a global analysis of each conformer to define the effect of iodide ions in the cavity by determining the value of the association constant. The possible quenching mechanism may be based on long-range through-space interactions between the buried chromophore and quencher in the aqueous phase. The discrepancies of the decay parameters between the albumins studied may be related with the accumulation of positive charge at the main and the back entrance to the Drug Site 1 where tryptophan residue is located.
      Graphical abstract image

      PubDate: 2016-06-15T17:06:42Z
       
  • Raman scattering or fluorescence emission? Raman spectroscopy study on
           lime-based building and conservation materials
    • Abstract: Publication date: 5 December 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 169
      Author(s): Zofia Kaszowska, Kamilla Malek, Emilia Staniszewska-Slezak, Karina Niedzielska
      This work presents an in-depth study on Raman spectra excited with 1064 and 532nm lasers of lime binders employed in the past as building materials and revealed today as valuable conservation materials. We focus our interest on the bands of strong intensity, which are present in the spectra of all binders acquired with laser excitation at 1064nm, but absent in the corresponding spectra acquired with laser excitation at 532nm. We suggest, that the first group of spectra represents fluorescence phenomena of unknown origin and the second true Raman scattering. In our studies, we also include two other phases of lime cycle, i.e. calcium carbonate (a few samples of calcite of various origins) and calcium oxide (quicklime) to assess how structural and chemical transformations of lime phases affect the NIR-Raman spectral profile. Furthermore, we analyse a set of carbonated limewashes and lime binders derived from old plasters to give an insight into their spectral characteristics after excitation with the 1064nm laser line. NIR-Raman micro-mapping results are also presented to reveal the spatial distribution of building materials and fluorescent species in the cross-section of plaster samples taken from a 15th century chapel. Our study shows that the Raman analysis can help identify lime-based building and conservation materials, however, a caution is advised in the interpretation of the spectra acquired using 1064nm excitation.
      Graphical abstract image

      PubDate: 2016-06-15T17:06:42Z
       
  • Water-soluble Hantzsch ester as switch-on fluorescent probe for
           efficiently detecting nitric oxide
    • Abstract: Publication date: 5 December 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 169
      Author(s): Hui-Li Wang, Fu-Tao Liu, Ai-Xiang Ding, Su-Fang Ma, Lan He, Lan Lin, Zhong-Lin Lu
      A water soluble Hantzsch ester derivative of coumarin, DHPS, was synthesized and successfully applied in the fluorescent sensing nitric oxide (NO) in aqueous solution. The fluorescence of probe DHPS is extremely weak, while its fluorescence was greatly switched on upon the addition of NO solution and showed high selectivity and sensitivity to NO. The limitation of the detection was calculated to be 18nM. The NO-induced aromatization of dihydropyridine in DHPS to pyridine derivative (PYS) proved to be the switching mechanism for the fluorescent sensing process, which was confirmed through spectra characterization and computation study. Cytotoxicity assay demonstrated both DHPS and PYS are biocompatible, the DHPS was successfully applied to track the endogenously produced NO in the RAW 264.7 cells.
      Graphical abstract image

      PubDate: 2016-06-15T17:06:42Z
       
  • Substituent effects on hydrogen bonding of aromatic amide-carboxylate
    • Abstract: Publication date: 5 October 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 167
      Author(s): Ibrahim Sen, Hulya Kara, Akın Azizoglu
      N-(p-benzoyl)-anthranilic acid (BAA) derivatives have been synthesized with different substituents (X: Br, Cl, OCH3, CH3), and their crystal structures have been analyzed in order to understand the variations in their molecular geometries with respect to the substituents by using 1H NMR, 13C NMR, IR and X-ray single-crystal diffraction. The carboxylic acid group forms classic OH⋯O hydrogen bonded dimers in a centrosymmetric R2 2(8) ring motifs for BAA-Br and BAA-Cl. However, no carboxylic acid group forms classic OH⋯O hydrogen bonded dimers in BAA-OCH 3 and BAA-CH 3 . The asymmetric unit consists of two crystallographically independent molecules in BAA-OCH 3 . DFT computations show that the interaction energies between monomer and dimer are in the range of 0.5–3.8kcal/mol with the B3LYP/6-31+G*, B3LYP/6-31++G*, B3LYP/6-31++G**, and B3LYP/AUG-cc-pVDZ levels of theory. The presence of different hydrogen bond patterns is also governed by the substrate. For monomeric compounds studied herein, theoretical calculations lead to two low-energy conformers; trans (a) and cis (b). Former one is more stable than latter by about 4kcal/mol.
      Graphical abstract image

      PubDate: 2016-06-15T17:06:42Z
       
  • A highly selective colorimetric and fluorescent turn-on chemosensor for
           Al3+ based on naphthalimide derivative
    • Abstract: Publication date: 5 October 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 167
      Author(s): Lei Kang, Zhi-Yong Xing, Xiao-Yuan Ma, Ya-Tong Liu, Yu Zhang
      A new chemosensor L based on the naphthalimide moiety was synthesized and characterized. L exhibited the high selectivity and sensitivity for Al3+ in CH3OH, along with colorimetric and fluorometric dual-signaling responses based on the joint contribution of the ICT and CHEF processes. A 1:1 stoichiometry for the L-Al3+ complex was formed with an association constant of 7.6×104 M−1, and the limit of detection for Al3+ was determined as 6.9μM. In addition, L was successfully applied to the determination of Al3+ in real water samples.
      Graphical abstract image

      PubDate: 2016-06-15T17:06:42Z
       
  • Sensing behavior and logic operation of a colorimetric fluorescence sensor
           for Hg2+/Cu2+ ions
    • Abstract: Publication date: 5 October 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 167
      Author(s): Tian He, Cuiling Lin, Zhengye Gu, Luonan Xu, Anle Yang, Yuanyuan Liu, Huajun Fang, Huayu Qiu, Jing Zhang, Shouchun Yin
      A BODIPY-based 1 as a colorimetric fluorescence sensor was synthesized, and its metal sensing property was investigated. 1 displayed high selectivity and sensitivity towards Hg2+ and Cu2+ ions among 15 different metal cations. The addition of Hg2+ and Cu2+ ions into 1 in CH3CN resulted in a significant bathochromic shift of the UV absorption spectra from 533nm to 560nm and 593nm, respectively, changing the corresponding colors from pink to purple and blue. When excited at 530nm, the fluorescence intensity of 1 was quenched over 75% upon addition of Hg2+ ions, while 1 with Cu2+ ions exhibited significant fluorescence enhancement with a 23nm red-shift. Based on these results, three logic gates (OR, IMPLICATION, and INHIBIT) were obtained by controlling the chemical inputs.
      Graphical abstract image

      PubDate: 2016-06-15T17:06:42Z
       
  • Efficiency improvement of new Tetrathienoacene-based dyes by enhancing
           donor, acceptor and bridge units, a theoretical study
    • Abstract: Publication date: 5 October 2016
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 167
      Author(s): Zahra Tavangar, Nazanin Zareie
      A series of metal free Tetrathienoacene-based (TTA-based) organic dyes are designed and investigated as sensitizers for application in dye sensitized solar cells (DSSCs). Density function theory and time dependent density function theory calculations were performed on these dyes at vacuum and orthodichlorobenzene as the solvent. Effects of changing π-conjugation bridges and different functional groups in acceptor and donor units were investigated. UV–Vis absorption spectra were simulated to show the wavelength shifting and absorption properties. Inserting nitro and acyl chloride functional groups in acceptor and NH2 in donor units leads to the reduction of HOMO-LUMO gap by lowering the lowest unoccupied molecular orbital (LUMO) energy level and raising the highest occupied molecular orbital (HOMO) energy level and the increase in effective parameters in DSSC' efficiency. The results show that changing spacer units from thiophene to furan has a great effect on electronic structure and absorption spectra. Investigation of the electron distributions of frontier orbitals shows the HOMO and LUMO localization in donor and acceptor, respectively. Some key parameters that were studied here include light harvesting efficiency, free energy of electron injection and open circuit photo-voltage.
      Graphical abstract image

      PubDate: 2016-06-15T17:06:42Z
       
 
 
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