Authors:Samir A. Abdel-Latif; H. Moustafa Abstract: 5-phenylazo-8-hydroxyquinoline and its newly metal complexes with Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) metal ions have been prepared and characterized using different analytical techniques. The complexes are distorted octahedral binding via one oxygen and nitrogen atoms of the ligand; two/three coordinated water molecules. 1:1 complexes contain one chloride or OH− ion and some complexes have one or two water of hydration whereas 1:2 complexes contain only two coordinated water molecules in their coordination spheres. All complexes behave as neutral in dimethylformamide (DMF). The electronic structure and non-linear optical parameters NLO of the complexes (ML and ML2) are investigated theoretically at the B3LYP/GEN level of theory. The geometries of the studied complexes are non-planner. The calculated EHOMO and ELUMO energies of the studied complexes were used to calculate the global properties; hardness (η), global softness (S) and electronegativity (χ). The total dipole moment (μtot), static total and anisotropy of polarizability (α, Δα) and static first hyperpolarizability (β) values were calculated and compared with urea as a reference compound. The studied complexes show promising optical properties.Newly 5-phenylazo-8-hydroxyquinoline complexes were prepared and characterized using different analytical and spectroscopic techniques. The electronic structure of the complexes are investigated theoretically at the B3LYP/GEN using LANL2DZ basis set for Mn, Co, Ni, Cu and Zn atoms and 6-311 G** basis set for C, H, N and O atoms. The non-linear optical parameters NLO and global properties of the studied complexes computed using B3LYP/LANL2DZ level of theory. PubDate: 2017-06-21T03:21:58.030574-05: DOI: 10.1002/aoc.3876
Authors:Zelin Cui; Xuefeng Bai, Yang Liu, Sheng Li Abstract: Palladium nanocrystals with a variety of shapes have received particular interest in recent years due to their unique properties in catalysis. Herein, Pd concave nanocubes with high-index facets (Pd-CNs) was synthesized by a simple water-based route without seeds using L-ascorbic acid (AA) as the reduction agent in the presence of CTAB. X-ray diffraction and transmission electron microscopy were employed to demonstrate the formation of concave structures with high-index facets of the Pd-CNs with an average size of 17.5 nm. The as-prepared Pd-CNs presented significantly higher catalytic activity than commercial Pd/C (an average particle size of 4.7 nm) in the electro-oxidation of methanol, but exhibited weaker property in Suzuki coupling reaction, which provided an evidence for the effect of shape and size on different reactions.Palladium concave nanocubes with high-index facets (Pd-CNs) was synthesized by a simple water-based route without seeds. The Pd-CNs (average size of 17.5 nm) presented significantly higher catalytic activity than commercial Pd/C (3.7 nm) in the electro-oxidation of methanol, but exhibited weaker property in Suzuki coupling reaction, which provided an evidence for the effect of shape and size on different reactions. PubDate: 2017-06-21T03:16:09.266741-05: DOI: 10.1002/aoc.3887
Authors:Chetan K. Modi; Naresh Solanki, Ravi Vithalani, Dikin Patel Abstract: Transition metal [M = VO (IV) and/or Cu (II)] complexes with Schiff base ligand, (Z)-2-((2-hydroxybenzylideneamino)phenol (H2L) have been entrapped in the super cages of zeolite-Y by Flexible Ligand Method. Synthesized materials have been characterized by preferential physico-chemical techniques such as inductively coupled plasma optical emission spectroscopy (ICP-OES), elemental analyses (CHN), fourier transmission infrared spectroscopy (FTIR), electronic and UV-reflectance spectra, Brunauer–Emmett–Teller (BET) surface area measurements, scanning electron micrographs (SEMs), X-ray diffraction patterns (XRD) and thermogravimetric analysis (TGA). The catalytic competence of zeolite-Y entrapped transition metal complexes was examined in Baeyer-Villiger (BV) oxidation of cyclopentanone using 30% H2O2 as an oxidant beside neat complexes to check the aptitude of heterogeneous catalysis over the homogeneous system. The effect of experimental variables such as mole ratio of substrate to an oxidant, amount of catalyst, reaction time, varying oxidants and solvents on the conversion of cyclopentanone was also tested. Under the optimized reaction conditions, one of the zeolite-Y entrapped transition metal complex viz. [VO(L)H2O]-Y [where L = (Z)-2-((2-hydroxybenzylideneamino)phenol] was found to be a potential contender by providing 80.22% conversion of cyclopentanone (TON: 10479.42), and the selectivity towards δ-valerolactone was 83.56%.Zeolite-Y entrapped transition metal complexes were examined to check the catalytic competence for Baeyer-Villiger (BV) oxidation of cyclopentanone using 30% H2O2 as an oxidant. Amongst them, optimal performance attained by [VO(L)H2O]-Y catalyst with 80.22% conversion of cyclopentanone and 83.56% selectivity towards δ-valerolactone. PubDate: 2017-06-19T00:10:35.460311-05: DOI: 10.1002/aoc.3910
Authors:Li-Jun Wang; Ling Peng, Bo Cen, Yu-Long Wang, Xian Tao, Ying-Zhong Shen Abstract: A series of para-toluene sulfonamide ligands [TsNHPr-i(HL1), TsNHBu-t(HL2), TsNHPh(HL3), TsNHPhMe-p(HL4), TsNHPhOMe-p(HL5)] were synthesized by amidation using para-toluene sulfonyl chloride reacting with different primary amines. A series of homoleptic lanthanide complexes (Ln L3, 1–10) (Ln = La, L = L1 (1), Ln = Gd, L = L2 (2), Ln = La, L = L2 (3), Ln = Gd, L = L2(4), Ln = La, L = L3 (5), Ln = Gd, L = L3 (6), Ln = La, L = L4 (7), Ln = Gd, L = L4(8), Ln = La, L = L5 (9), Ln = Gd, L = L5 (10)) were prepared by amine elimination reactions of the ligands with Ln[N(SiMe3)2]3 (Ln = La, Gd). Complexes 1, 3, 5, 7 and 9 were all characterized by NMR spectra, and the structures of complex 3 was determined by single-crystal X-ray diffraction. Complex 3 crystallizes a binuclear cluster, consisting of two La3+ and six (TsNBu-t)− anions. Three (TsNBu-t)− anions are chelating to each La3+ as bidentate model with O and N forming three-membered chelate rings; one of three anions is bridging to another La3+ via oxygen. All complexes were characterized using elemental analysis and infrared spectra. The catalytic properties of complexes 1–10 for the ring-opening polymerization of ε-caprolactone were studied and the results showed that all complexes are efficient initiators for this ring-opening polymerization reaction.The preparation of ten lanthanide complexes bearing para-toluene sulfonamide ligands were obtained by the reaction of Ln[N(TMS)2]3 (Ln = La, Gd) with para-toluene sulfonamides is described. The crystal structure of Complex 3 was determined and discussed. The catalytic properties of complexes 1 - 10 for the ring-opening polymerization of ε-caprolactone were studied and the results showed that all complexes are efficient initiators for this ring-opening polymerization. PubDate: 2017-06-19T00:06:18.474826-05: DOI: 10.1002/aoc.3828
Authors:Najmedin Azizi; Mahtab Edrisi, Faezeh Abbasi Abstract: Mesoporous silica SBA-15 functionalized with N-methylpyrrolidonium-zinc chloride based deep eutectic solvent (DES) is found to be a more efficient and reusable catalyst for a convenient N-formylation of a variety of amines at room temperature. N-Formylation of primary, secondary as well as heterocyclic amines have been carried out in good to excellent yields by treatment with formic acid in low loading of DES/SBA-15 an environmentally benign catalyst for the first time. The DES/SBA-15 catalyst, which possesses both Brønsted and Lewis acidities as well as an active SBA-15 support, makes this procedure quite simple, reusable, more convenient and practical. This catalyst was tolerant of a wide range of functional groups, and it can be reused for four runs without obvious deactivation.DES/SBA-15 an attractive nanocomposite, was employed as a more efficient and reusable catalyst for a convenient N-formylation of a variety of amines. Various primary, secondary as well as heterocyclic amines were tested and proved successful using this green methodology under mild reaction condition. This nanocomposite was tolerant of a wide range of functional groups, and it can be reused for four runs without obvious deactivation. PubDate: 2017-06-19T00:06:01.673305-05: DOI: 10.1002/aoc.3901
Authors:Lixia Fu; Wenxiu Deng, Lujie Liu, Yanqing Peng Abstract: Functionalized natural polysaccharides are attractive supports for colloidal metal nanocatalysts due to their abundance, cheapness, biocompatibility and biodegradability. In this study, isocyanate–functionalized starch was prepared by treating with diisocyanate. Polyethylenimine grafted onto starch via the formation of urea linker. The palladium nanoparticles deposited starch PEIS@Pd(0) was obtained through a chelating–in situ reduction procedure. Characterization of these materials was done using Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X–ray diffraction, and inductive coupled plasma atomic emission spectrometry. The catalytic activity of PEIS@Pd(0) was then tested in two series of model reactions: Suzuki–Miyaura coupling and transfer hydrogenation. The catalyst could be recovered by simple filtration and was reused for five times without significant loss of catalytic activity, which confirmed the good stability of the catalyst.Palladium nanoparticles were supported on polyethylenimine–grafted starch which could be employed as efficient, ecofriendly and reusable heterogeneous catalyst for Suzuki–Miyaura coupling and transfer hydrogenation. PubDate: 2017-06-16T04:20:59.602994-05: DOI: 10.1002/aoc.3853
Authors:Ali Ramazani; Mehdi Khoobi, Fariba Sadri, Roghayeh Tarasi, Abbas Shafiee, Hamideh Aghahosseini, Sang Woo Joo Abstract: Palladium immobilized magnetic nanoFe3O4@hyperbranched polyethylenimine (Fe3O4@HPEI.Pd) was prepared according to a simple and cost effective pathway and it was employed as a new efficient and selective organic–inorganic hybrid nanocatalyst for the aqueous oxidation of primary and secondary alcohols to their corresponding products in good yields applying oxone (potassium hydrogen monopersulfate) and H2O2 as an oxidant at room temperature. Moreover, the catalytic system was reused at least 13 times without significant loss of activity. The complete characterization of this efficient nanocatalyst was investigated by FTIR, UV–Vis, TEM, SEM, XRD, TGA, VSM, ICP and EDX techniques.Modifying the surfaces of Fe3O4 with the blend of hyperbranched polyethylenimine (HPEI) and [3-(2,3-epoxypropoxy)propyl]trimethoxysilane (EPO), then the adsorption of Pd inside its shell to produce fe3o4@hpei.pd, as an active, stable, and reusable catalyst for the selective oxidation of alcohols. PubDate: 2017-06-13T03:50:52.729174-05: DOI: 10.1002/aoc.3908
Authors:Ayman A. Abdel Aziz; Sabry H. Seda Abstract: The tetradentate Schiff base ligand (SB), N,N′-bis-(2-mercaptophenylimine)-2,5-thiophenedicarboxaldehyde was prepared via condensation of 2,5-thiophene-dicarboxaldehyde with 2-aminothiophenol in a 1:2 molar ratio by conventional method. Additionally, its Co(II), Ni(II), Cu(II) and Zn(II) complexes have been synthesized and fully characterized by elemental analysis, FT-IR, 1H NMR, 13C NMR, UV–Vis, ESR, ESI-mass, conductivity and magnetic susceptibility measurements. Spectral studies suggested that, the Schiff base coordinate metal ions through the azomethine N- and deprotonated thiol S- atoms. Based on UV–Vis absorption and magnetic susceptibility data, tetrahedral geometry was assigned for both Co(II) and Zn(II) complexes, whereas on the other hand, square planar geometry for both Ni(II) and Cu(II) complexes. The Schiff base and its metal complexes were screened for their in vitro antimicrobial activity by minimum inhibitory concentration (MIC) method. Free radical scavenging activity of the novel compounds was determined by elimination of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals. In addition, the interactions of the free ligand and its complexes with calf thymus DNA (CT-DNA) were explored using absorption, emission and viscosity measurements techniques.Four first row transition metal complexes were synthesized form novel tetradentate Schiff base with N2S2 coordination sites namely, N,N′-bis-(2-mercaptophenylimine)-2,5-thiophenedicarboxaldehyde under aerobic and thermal conditions The novel compounds were fully characterized by elemental analysis, FT-IR, 1H NMR, 13C NMR, UV–Vis, ESR ESI-mass, conductivity, and magnetic susceptibility measurements. Biological activity assessment of novel compounds was performed via studying antimicrobial activity, antioxidant scavenging and DNA interactions. PubDate: 2017-06-13T03:45:34.120556-05: DOI: 10.1002/aoc.3879
Authors:Hashem Sharghi; Iman Ghaderi, Mohammad Mahdi Doroodmand Abstract: One-pot and three components C-S bond formation reactions in thioethers and S-aryl-carbamodithioates have been catalyzed by a copper heterogeneous nano-catalyst supported on modified AlPO4 under different reaction conditions. The above-mentioned nano-catalyst has been characterized by various techniques such as SEM, TEM, AFM, XRD, FT-IR, UV–Vis, CV, BET, TGA, ICP and XPS spectrometry and its particle size was estimated to be between 60–110 nm. Finally, the reusability of the catalyst up to ten cycles without any significant leaching is one of the outstanding properties of the catalyst.Efficient, one-pot and three components C-S bond formation reactions in thioethers and S-aryl-carbamodithioates have been catalyzed by a copper heterogeneous nano-catalyst supported on modified AlPO4 was developed. The nano-catalyst has been characterized by SEM, TEM, AFM, XRD, FT-IR, UV–Vis, CV, BET, TGA, ICP and XPS spectrometry. PubDate: 2017-06-13T03:35:40.742714-05: DOI: 10.1002/aoc.3869
Authors:Mosayeb Sarvestani; Roya Azadi Abstract: In this work, graphene oxide was functionalized with chitosan (GO-Chit) followed by a simple approach for immobilization of palladium nanoparticles onto a chitosan grafted graphene oxide surface. The Pd-nanocomposite (GO-Chit-Pd) was characterized using Transmission Electron Microscopy (TEM), Fourier transforms infrared spectroscopy (FT-IR), and X-ray diffraction (XRD) measurements. The catalytic activity of the prepared heterogeneous graphene oxide functionalized chitosan-palladium (GO-Chit-Pd) was investigated in term of C-N coupling reaction (Buchwald-Hartwig amination reaction of aryl halides) yielding products of N-arylamines. The easy purification, convenient operation, and environmental friendliness, combined with a high yield, render this method viable for use in both laboratory research and larger industrial scales. Studying the reusability of the catalyst in this work showed that it could be reused for five times without obvious loss in catalytic activity.Graphene oxide was functionalized with chitosan (GO-Chit) followed by a simple approach for immobilization of palladium nanoparticles onto a chitosan grafted graphene oxide surface. The catalytic activity of the prepared heterogeneous graphene oxide functionalized chitosan-palladium (GO-Chit-Pd) was investigated in term of C-N coupling reaction (Buchwald-Hartwig amination reaction of aryl halides) yielding products of N-arylamines. PubDate: 2017-06-13T03:31:07.824221-05: DOI: 10.1002/aoc.3906
Authors:Niloufar Dorosti; Bahram Delfan, Marzieh Khodadadi Abstract: Nanorods of a diorganotin phosphonic diamide with formula [Sn(CH3)2(Cl)2(L)2]{L = C6H5(O)P(NHC6H11)2} have been synthesized by sonochemical processes at different concentrations without any surfactant or capping agent. The structure and morphology of the prepared complex were investigated by using SEM-EDAX, XRD, DLS, UV–Vis and FT-IR spectroscopy. Nanoparticles with well-defined rod shapes and sizes in the range 30–40 nm have been obtained. Also bulk form of the titled complex was synthesized and characterized by 1H, 13C, 31P, 119Sn NMR, UV–Vis and FT-IR spectroscopy and compared with its nano-size. The thermal stabilities at bulk and nano-size scale have been studied by thermal gravimetric (TG) and differential thermal analysis (DTA). Further, SnP2O7 nanoparticles were synthesized by direct calcination at 730 °C under air atmosphere and characterized using XRD, SEM, and TEM. From XRD measurements, we determined the mean size of the crystallites about 27.4 nm. It is found that the size and morphology of the tin pyrophosphate nano-structures are dependent upon the particles size of precursor compound as well. Two different forms of metal coordination compound (1a, 1b) and the corresponding ligand (L) were screened for their antibacterial activity against the selected Gram-positive and Gram-negative bacteria, showing bactericidal activity for complexes 1a and 1b. In vitro cytotoxicity of compounds was studied against human carcinoma cell lines, A2780 (ovarian cancer) and PC-3 (prostate cancer). Results indicated that 1a and 1b possess relatively strong cytotoxic activity against cancer cells with IC50 values ranging from 93.2 to 376.2 μM for two exposure time (24 and 48 h).A rod-structure diorgatin phosphonic diamide have been synthesized by two different methods as precursor for fabrication of SnP2O7 nano-structures. PubDate: 2017-06-13T02:55:43.333176-05: DOI: 10.1002/aoc.3875
Authors:Amani Abu Shamma; Hijazi Abu Ali, Shayma Kamel Abstract: The synthesis of mononuclear cobalt(II/III) complexes with two different ligands (complex 2: [Co(valp)2(2,9-dmp)] and complex 3: [Co(valp)2(H2O)(1,10-phen)]) was investigated and the characterization of both complexes was achieved using IR, UV–Vis, and single crystal X-ray diffraction. Using single crystal X-ray diffraction, the crystal structure of each of the complexes was determined. Additionally, the biological activity of these complexes was studied in five gram-positive and four gram-negative bacterial strains. Whereas in all gram-negative bacteria tested, cobalt valproate complexes did not show any anti-bacterial activity, both complexes had effects on gram positive bacteria. Complex 2 demonstrated good anti-bacterial activity against all gram-positive bacteria with inhibition zone diameter (IZD) ranging between 15–28 mm. Complex 3 exhibited low inhibition activity against all gram-positive bacteria except E. faecalis with IZD ranging between 11.3–13.7 mm. Moreover, as an indication of its uses as industrial catalyst, the rate of bis(p-nitrophenyl) phosphate (BNPP) hydrolysis when catalyzed by these complexes was measured at different temperatures, concentrations and pH. Complex 2 proved to be a better catalyst to induce the hydrolysis of BNPP.BNPP hydrolysis by complex 2 in MeOH /HEPEs buffer solution with different pH values under the selected conditions (T = 25 °C, [complex 2] = 2 × 10−3 M and [BNPP] = 1 × 10−4 M). PubDate: 2017-06-07T03:35:45.51204-05:0 DOI: 10.1002/aoc.3904
Authors:Mojtaba Amini; Mohammad Mahdi Najafpour, Saeideh Salimi, Sakine Ramezani, Fatemeh Ashouri, Ghodrat Mahmoudi Abstract: For the first time, iron oxide on carbon aerogel, amine functionalized carbon nanotube, black carbon and carboxylic acid functionalized carbon nanotube in the presence of H2O2 was reported as an efficient and stable catalyst for the selective oxidation of sulfides and alcohols. The catalysts were characterized by scanning electron microscopy, energy-dispersive spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy and atomic absorption spectroscopy. In the next step, catalytic reactivity toward sulfide to sulfoxide and alcohol to aldehyde/ketone oxidation in the presence of H2O2 was studied and discussed.Iron oxide supported on carbon-based are efficient catalysts for sulfide to sulfoxide oxidation in the presence of H2O2. PubDate: 2017-06-07T03:31:12.061167-05: DOI: 10.1002/aoc.3892
Authors:Maryam Keram; Haiyan Ma Abstract: A series of zinc silylamido complexes bearing non-symmetric β-diketiminate ligands were synthesized and structurally characterized. Ring-opening polymerization (ROP) of rac-lactide catalyzed by these zinc complexes afforded heterotactic polylactides at room temperature (Pr = 0.79 ~ 0.83 in THF). The steric and electronic characteristics of the ancillary ligands showed significant influence on the polymerization performance of the corresponding zinc complexes. All these zinc complexes also showed moderate activities toward the polymerization of ε-caprolactone at ambient temperature in toluene, producing polycaprolactones (PCLs) with high molecular weights and moderate polydispersities. PCL-b-PLLA copolymers could be obtained via three different copolymerization strategies (one-pot polymerization, and sequential addition of the two monomers in either order) by adopting complex 6 as the initiator through the adjustment of reaction temperatures. The diblock nature of the copolymers was confirmed by 13C NMR spectroscopy and DSC analysis.A series of β-diketiminate zinc complexes were synthesized and explored as active initiators for the polymerization of rac-lactide, ε-caprolactone and their copolymerization. PCL-b-PLLA copolymers could be obtained via three different feeding strategies through the adjustment of reaction temperatures. PubDate: 2017-06-07T03:30:33.605298-05: DOI: 10.1002/aoc.3893
Authors:Kemal Yavuz; Hasan Küçükbay Abstract: A number of novel benzimidazole salts were synthesized and their structures were determined using 1H NMR, 13C NMR and infrared spectroscopic techniques and elemental analysis. A catalyst system consisting of Pd(OAc)2 and copper nanoparticles in the presence of Cs2CO3 and incorporating the novel benzimidazole salts in poly(ethylene glycol) solvent significantly improved the yields of Sonogashira reactions between aryl halides and phenylacetylene under microwave irradiation in 10 min.We have developed an efficient, simple and environmentally benign catalytic system incorparating novel benzimidazole salts for the Sonogashira cross coupling reaction.the catalyst system consisting of Pd(OAc)2, CuNPc, benzimidazole salts, Cs2CO3 in PEG300 can be recycled at least tree times without loss of activity in short reaction time (10 min) without any palladium black formation. PubDate: 2017-06-07T03:20:55.860566-05: DOI: 10.1002/aoc.3897
Authors:Tao Feng; Ranxiao Tang, Ningzhao Shang, Cheng Feng, Shutao Gao, Chun Wang Abstract: A facile and efficient method for facilitating hydrogen generation from formaldehyde aqueous solution was developed using Pd nanoparticles supported on CeO2 (Pd/CeO2) as the catalyst. The prepared Pd/CeO2 catalyst exhibited 100% H2 selectivity and excellent catalytic activity for formaldehyde dehydrogenation with the initial rate of 2089 ml min−1 gPd−1 at room temperature and atmospheric pressure without any extra additive. The prepared catalyst was stable and reusable, and its catalytic activity kept almost unchanged after it was reused for the fifth run. Therefore, it is considered that this Pd/CeO2 based hydrogen generation system may serve as an alternative hydrogen supply candidate for practical application.Pd metallic nanoparticles were successfully supported onto the CeO2 by a facile approach. PdCl42− was attracted to the surface of CeO2 first then was reduced in the presence of reducing agent. The Pd/CeO2 exhibited high activity for the dehydrogenation of HCHO at room temperature. PubDate: 2017-06-07T03:20:53.920191-05: DOI: 10.1002/aoc.3889
Authors:Razieh Maleki; Eskandar Kolvari, Mehdi Salehi, Nadiya Koukabi Abstract: Fe3O4 magnetic nanoparticles (MNPs) were obtained using a reduction–precipitation method. These MNPs were modified with cysteamine hydrochloride. This catalyst was characterized using a number of physicochemical measurements. The Fe3O4–cysteamine MNPs, as an efficient and heterogeneous catalyst, were successfully used for Knoevenagel condensation under mild conditions. The activity of this nanomagnetic catalyst in the Knoevenagel condensation of aromatic aldehydes and malononitrile is described. Easy preparation of the catalyst, easy work-up procedure, excellent yields and short reaction times are some of the advantages.Fe3O4 magnetic nanoparticles (MNPs) were obtained by a reduction–precipitation method. These MNPs were modified with cysteamine hydrochloride. The resulting organic magnetic salt nanocatalyst was used in the Knoevenagel condensation of aromatic aldehydes and malononitrile or dimedone. PubDate: 2017-06-06T04:15:56.996611-05: DOI: 10.1002/aoc.3795
Authors:Fatereh Asghari-Haji; Kurosh Rad-Moghadam, Nosrat O. Mahmoodi, Tayyebeh Tonekaboni, Najmeh Rahimi Abstract: A nano-magnetic core-shell composite fabricated of a unique zwitterionic chitosan-derived coating and cobalt ferrite core was found to be a green and reusable heterogeneous catalyst for efficient synthesis of pyrano[3,2-c]quinoline and spiro-oxindole derivatives in high to excellent yields. Due to having negative charges at its outermost layer and a high magnetization, the catalyst is finely dispersed in ethanol and can be easily separated from reaction mixtures by using a simple external magnet. It is reasonably stable as can be reused several times without appreciable loss of catalytic activity.Cobalt ferrite nano-particles encapsulated with the chitosan derivative containing 12% of the zwitterionic N-(4-sulfonylbutyl) grafts have shown good dispersity in ethanol and water. The IR spectrum of this nano-composite is better interpreted as displaying the formation of covalent bonds between its inorganic and bioorganic components. The nano-composite appeared as a soft and efficient catalyst in the synthesis of pyrano[3,2-c]quinolin-4-ones. PubDate: 2017-06-06T04:15:45.326661-05: DOI: 10.1002/aoc.3891
Authors:Wail Al Zoubi; Abbas Ali Salih Al-Hamdani, Susan Duraid Ahmed, Young Gun Ko Abstract: A new Azo-Schiff base ligand L was prepared by reaction of m-hydroxy benzoic acid with (Schiff base B) of 3-[2-(1H–indol-3-yl)-ethylimino]-1.5-dimethyl-2-phenyl-2,3-dihydro-1H-pyrazol-4-ylamine. This synthesized ligand was used for complexation with different metal ions like Ni(II), Co(II), Pd(II) and Pt(IV) by using a molar ratio of ligand: metal as 1:1. Resulted compounds were characterized by NMR (1H and 13C), UV–vis spectroscopy, TGA, FT-IR, MS, elemental analysis, magnetic moment and molar conductivity studies. The activation thermodynamic parameters, such as ΔE*, ΔH*, ΔS*, ΔG*and K are calculated from the TGA curves using Coats-Redfern method. Hyper Chem-8 program has been used to predict structural geometries of compounds in gas phase. The biological activities of Schiff base and its complexes had been tested in vitro against, two Gram positive bacteria (Bacillus subtillis and Staphylococcus aureus) and two Gram negative bacteria (Escherichia coli and Pseudomonas aeruguinosa).Prepared ligand was used for complexation with different metal cations like Ni(II), Co(II), Pd(II) and Pt(IV) by using a molar ratio of ligand: metal as 1:1. These complexes were characterized by NMR (1H and 13C), UV–vis spectroscopy, TGA, FT-IR, MS, elemental analysis, magnetic moment and molar conductivity studies. Biological activities of Schiff base complexes had been tested in vitro against, two Gram positive bacteria (Bacillus subtillis and Staphylococcus aureus) and two Gram negative bacteria (Escherichia coli and Pseudomonas aeruguinosa). PubDate: 2017-06-02T04:01:01.217664-05: DOI: 10.1002/aoc.3895
Authors:W.H. Mahmoud; N.F. Mahmoud, Gehad G. Mohamed Abstract: Physicochemical studies were performed to study new ferrocene based Schiff base ligand (HL), (Z)-(4-(1-((2-carboxycyclohexa-2,4-dien-1-yl)imino)ethyl)[bis(η5cyclopenta-1,3-dien-1 yl)]iron with some transition metal ions to form a series of ferrocenyl derivatives bearing transition metal complexes of the type [M(L)Cl(H2O)3] (M = Ni(II), Cu(II)), [M(L)Cl(H2O)3]nH2O (M = Mn(II) (n = 1), Co(II) (n = 1), Zn(II) (n = 2) and Cd(II) (n = 3)) and [M(L)Cl(H2O)3]Cl.nH2O (M = Cr(III) (n = 2) and Fe(III) (n = 1)). The new ligand and metal ion complexes have been prepared and characterized by IR, UV-Vis, 1H-NMR, TG/DTA, elemental analysis and mass spectrometry. The TGA/DTG analysis revealed that the ferrocene precursors decompose spontaneously to form iron(II) oxide. The molecular and electronic structure of the ligand (HL) was optimized theoretically and the quantum chemical parameters were calculated. The molecular structure with a variety of functionalities can be used to investigate the coordination sites and the total charge density around each atom. DFT-based molecular orbital energy calculations of the new ligand have been also studied. All of the complexes were screened against a panel of Gram (+) bacteria: Streptococcus pneumoniae and Bacillis subtilis, Gram (−) bacteria: Pseudomonas aeruginosa and Escherichia coli and panel of fungi: Aspergillus fumigatu, Syncephalastrum racemosum, Geotricum candidum and Candida albicans. Anticancer activity screening for the tested compounds using 4 different concentrations of HL ligand against human tumor cells of breast cancer cell line MCF-7 were obtained. Molecular docking was used to predict the binding between HL ligand and human-DNA-Topo I complex (PDB ID: 1SC7), the receptors of breast cancer mutant oxidoreductase (PDB ID: 3HB5), crystal structure of Escherichia coli (PDB ID: 3T88), to identify the binding mode and the crucial functional groups interacting with the three proteins.Schiff base ligand, HL and its eight new transition metal complexes were prepared and characterized using different tools.The results of antimicrobial assay of ligand and the complexes suggested the complexes exhibited highest antibacterial, antifungal activity and inhibitory activity against breast carcinoma.Molecular docking studies of the free Schiff base ligand and Mn(II) complex with receptors of different proteins reveal that HL ligand and Mn(II) complex show highest binding ability. PubDate: 2017-06-02T04:00:50.367137-05: DOI: 10.1002/aoc.3858
Authors:Reza Fareghi-Alamdari; Mohammad S. Saeedi, Farhad Panahi Abstract: A new bis(N-heterocyclic carbene) (NHC) palladium complex supported on silica coated magnetic nanoparticles (MNPs) was prepared using the reaction of synthesized Pd-NHC complex with MNPs. The Pd-NHC complex was prepared using the reaction of a hydroxyl-functionalized bis-imidazolium ionic liquid. The Pd-NHC organometallic complex was used as a heterogeneous recyclable and active catalyst in the Suzuki-Miyaura reaction and various aryl halides were coupled with arylboronic acids in order to synthesize diverse biaryls in good to excellent yields. The prepared catalyst was characterized by use of some different microscopic and spectroscopic techniques including elemental analysis, FT-IR spectroscopy, diffuse reflectance UV–Vis spectrophotometery, scanning electron microscopy (SEM), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM) and X-ray diffraction (XRD). The Pd-NHC catalyst system is a magnetic reusable catalyst and it can be separated from the reaction mixture using an external magnetic field. The catalyst was reusable in the Suzuki-Miyaura coupling reaction at least for 6 times without significant decreasing in its catalytic activity.Silica coated magnetic nanoparticles (MNPs) was modified with a bis(N-heterocyclic carbene) (NHC) palladium complex in order to synthesize a novel Pd-NHC complex for application in carbon-carbon coupling reactions. Pd-NHC as a magnetic reusable heterogeneous catalyst showed high reactivity in Suzuki-Miyaura coupling reaction and it was reusable for six times without significant decreasing in its catalytic activity. PubDate: 2017-06-02T04:00:35.086198-05: DOI: 10.1002/aoc.3870
Authors:Xiaojun Ma; Guanghui Lv, Xu Cheng, Weijian Li, Rui Sang, Yong Zhang, Qiantao Wang, Li Hai, Yong Wu Abstract: An environmentally friendly palladium(II) catalyst supported on cyclodextrin-modified h-BN was successfully prepared. The catalyst was characterized by FT-IR, SEM, TG, XRD and XPS, and the loading level of Pd in h-BN@β-CD@Pd(II) was measured to be 0.088 mmol g−1 by ICP. It exhibits excellent catalytic activity for the Suzuki and Heck reactions in water, and can be easily separated and consecutively reused for at least nine times. In addition, a series of pharmacologically interesting products were successfully synthesized using this catalyst to demonstrate its potential applications in pharmaceutical industries. Above all, this work opens up an interesting and attractive avenue for the use of cyclodextrin-functionalized h-BN as an efficient support for hydrophilic heterogeneous catalysts.An environmentally friendly palladium(II) catalyst supported on cyclodextrin-modified h-BN was successfully prepared. It exhibits excellent catalytic activity for the Suzuki and Heck reactions in water, and can be easily separated and consecutively reused for at least nine times. In addition, a series of pharmacologically interesting products were successfully synthesized using this catalyst to demonstrate its potential applications in pharmaceutical industries. PubDate: 2017-06-02T03:55:54.159265-05: DOI: 10.1002/aoc.3854
Authors:Amir Homayoun Keihan; Hamed Veisi, Parsia Mohammadi Biabri Abstract: In the present study, we carried out a chemical synthesis and characterization of Fe3O4@PEG-Au as a core/shell nanocomposite in an aqueous solution by the chemical co-precipitation of Fe3+ and Fe2+ ions and encapsulated it by polyethylene glycol (PEG) in order to enhance hydrophilicity and biocompatibility of gold ions and immobilize them in the presence of NaBH4 as a reducing agent. The nanostructures were characterized with FT-IR, FESEM, EDS, WDX, VSM, ICP-MS, and TEM. The antimicrobial activities of the nanostructures were tested against pathogenic microorganisms, including Staphylococcus aureus, Escherichia coli, and Candida albicans by broth microdilution method according to the methods of the Clinical Laboratory Standard Institute (CLSI). The toxicity of the nanostructures was tested against animal cell line based on MTT assay. The synthesized core/shell nanostructures had a good activity against the representative microorganisms of public health concern and revealed an insignificant toxicity against animal cell line.In this investigation, we synthesizing and characterizing an inorganic-organic hybrid Fe3O4@PEG-Au as an antimicrobial agent that was considered to be a promising tool due to its chemical stability, negligible toxicity, high hydrophlicity, heat resistance, and long life. PubDate: 2017-06-02T03:55:42.319167-05: DOI: 10.1002/aoc.3873
Authors:Ali Pourjavadi; Mohadeseh Doroudian, Azardokht Abedin-Moghanaki, Craig Bennett Abstract: Due to the high activity of Au nanoparticles (NPs) for various reactions, many researchers have tried to develop heterogeneous catalysts in order to prevent irreversible agglomeration of Au NPs. Herein, magnetic graphene oxide modified with polyaniline (PANI) was used as a support for Au NPs that brings together advantages including: uniform dispersal of the catalyst in water,alarge surface area related to the graphene oxide; easy electron transfer in chemical reactions and good attachment of Au NPs to the support associated with PANI; and finally facile recovery in the presence of a magnetic field. Catalytic reduction of different analytes (Congo red, methylene blue, rhodamine B and 4-nitro phenol) was evaluated in the presence of NaBH4 and the results show high catalytic activity of the catalyst. The catalyst was thoroughly characterized using various methods including FTIR, XRD, XPS, FE-SEM and HRTEM analyses while its catalytic activity was evaluated via reduction of different analytes.-synthesis of magnetic graphene oside modified with polyaniline as a heterogeneous support for Au nanoparticles.-comprehensive investigation of characteristics of the catalyst.-reduction of dyes and nitroaromatic compounds via a convenience method. PubDate: 2017-06-02T03:50:53.872787-05: DOI: 10.1002/aoc.3881
Authors:Si-Tong Li; Zhong-Ying Ma, Xin Liu, Jin-Lei Tian, Shi-Ping Yan Abstract: Five new mononuclear zinc(II) complexes containing ligands with extended planar phenanthroline moieties (dipyrido-[3,2-a:2′,3′-c]phenazine (dppz) or dipyrido[3,2-d:2′,3′-f] quinoxaline (dpq)), namely [Zn(dppz)(acac)2]⋅CH3OH (1), [Zn(dppz)(dbm)(OAc)] (2), [Zn(dpq)(dbm) (OAc)] 1.5H2O (3), [Zn(dpq)(tfnb)(OAc)] (4) and [Zn(dpq)(tfnb)2] (5), where acac = acetylacetonate, tfnb = benzoyltrifluoroacetone and dbm = dibenzoylmethane, were synthesized and structurally characterized. The binding ability of complexes 1–5 with calf thymus DNA was investigated by spectroscopic titration methods and viscosity measurements. Results indicate that all complexes bind to calf thymus DNA via intercalative mode, and the DNA binding affinities of dppz complexes 1 and 2 are apparently stronger than those of dpq complexes 3–5. DNA photocleavage experiments reveal that these complexes are efficient DNA cleaving agents and they are more active in UV-A (365 nm) than in visible light. In particular, the in vitro cytotoxicity of the complexes for human cancer cell line A549 demonstrates that the five compounds have anticancer activity with low IC50 values. Meanwhile, interaction of the complexes with bovine serum albumin investigated using UV–visible and fluorescence methods indicates that all complexes can quench the intrinsic fluorescence of bovine serum albumin in a static quenching process.Five mononuclear zinc(II) complexes were synthesized and their binding modes to calf thymus DNA investigated using spectroscopic and viscosity measurements. These complexes have good activities as chemical nucleases and can quench the intrinsic fluorescence of bovine serum albumin in a static quenching process. PubDate: 2017-06-02T03:45:46.215879-05: DOI: 10.1002/aoc.3802
Authors:Pan-Pan Shen; Min-Min Zhu, Ning Ren, Jian-Jun Zhang, Shu-Ping Wang Abstract: Four new lanthanide complexes [Ln(4-EBA)3(5,5′-DM-2,2′-bipy)]2·2C2H5OH (Ln = Ho (1), Tb (2), Er (3)); [Ln(4-EBA)3(4-EBAH)(5,5′-DM-2,2′-bipy)]2 (Ln = Eu(4); 4-EBA =4-ethylbenzoate; 5,5′-DM-2,2′-bipy =5,5′-dimethy-2,2′-bipyridine; 4-EBAH = 4-ethylbenzoic acid) have been synthesized and characterized by elemental analysis and IR spectra. The single crystal results reveal that complexes 1–3 are isostructural. It is worth noting that the mole ratios of the carboxylate ligands and neutral ligands is 4:1 in complex 4, which is different from the former and has been rarely reported. Nevertheless, all complexes are connected to form 1D chain by π···π wake staking interactions. Additionally, the complexes 2 (Tb(III)) and 4 (Eu(III)) exhibit characteristic luminescent properties, indicating that ligands can be used as sensitizing chromophore in these systems. The thermal decomposition mechanism of the complexes has been investigated by TG/DSC–FTIR technology. Stacked plots of the FTIR spectra of the evolved gases show complexes broken down into H2O, CO2, and other gaseous molecules as well as the gaseous organic fragments. The studies on bacteriostatic activities of complexes show that four complexes have good bacteriostatic activities against Candida albicans but no bacteriostatic activity on Escherichia coli, and Staphylococcus aureus. Additionally, the complexes 1 to 3 have better bacteriostatic activities on Candida albicans than complex 4.Complexes 1–4 are connected to form 1D chain by π···π wake staking interactions. The luminescent properties of complex 2 and 4 have also been studied. The thermal decomposition mechanism of title complexes were obtained by TG and coupled TG-FTIR technique. The antibacterial performance of ligands and title complexes were evaluated by the filter paper disc diffusion method. PubDate: 2017-05-30T22:20:43.30851-05:0 DOI: 10.1002/aoc.3886
Authors:Rahim Ghadari; Hassan Namazi, Mohammad Aghazadeh Abstract: The amino acid arginine was used to modify the surface of graphene oxide nanosheets and then nickel-substituted cobalt ferrite nanoparticles were supported on those arginine-grafted graphene oxide nanosheets (Ni0.5Co0.5Fe2O4@Arg–GO). The prepared Ni0.5Co0.5Fe2O4@Arg–GO was characterized using flame atomic absorption spectroscopy, inductively coupled plasma optical emission spectrometry, energy-dispersive spectroscopy, Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, Raman spectroscopy, X-ray diffraction, thermogravimetric analysis, scanning electron microscopy and transmission electron microscopy. The application of Ni0.5Co0.5Fe2O4@Arg–GO as a catalyst was examined in a one-pot tandem oxidative cyclization of primary alcohols with o-phenylenediamine to benzimidazoles under aerobic oxidation conditions. The results showed that 2-phenylbenzimidazole derivatives were successfully achieved using Ni0.5Co0.5Fe2O4@Arg–GO nanocomposite catalyst via the one-pot tandem oxidative cyclization strategy.Chemical attachment of arginine on the surface of graphene oxide nanosheets was carried out for the preparation of a green support for immobilization of nickel-substituted cobalt ferrite nanoparticles. The prepared catalyst showed efficient activity and reusability for the one-pot tandem oxidative cyclization of primary alcohols with o-phenylenediamines to benzimidazoles under aerobic oxidation conditions. PubDate: 2017-05-30T22:20:31.584963-05: DOI: 10.1002/aoc.3859
Authors:Abu Taher; Meenakshi Choudhary, Debkumar Nandi, Samarjeet Siwal, Kaushik Mallick Abstract: Polymer-supported palladium was synthesized by applying a single-step wet chemical synthesis route and the resultant composite material was characterized by means of various techniques. Infrared and UV–visible spectra provided information on the chemical structure of the polymer. Microscopy techniques showed the general morphology of the polymer. The oxidation state of palladium was determined using the X-ray photoelectron spectroscopy method. The synthesized material was applied as a heterogeneous catalyst for the Heck coupling reaction and also as an electrocatalyst for the oxidation of cysteine.Multifunctional polymer supported palladium catalyst for the (a) Heck coupling reaction and (b) electrochemical cysteine oxidation. PubDate: 2017-05-30T22:15:44.959558-05: DOI: 10.1002/aoc.3898
Authors:Yi-Rang Lin; Chien-Cheng Chiu, Huai-Tsu Chiu, Dong-Sheng Lee, Ta-Jung Lu Abstract: Bis-benzimidazolium salts were prepared successfully from commercially available and inexpensive o-phenylenediamine through a series of simple reactions. The bis-NHC-Pd complexes prepared in situ can catalyze Suzuki-Miyaura cross-coupling reaction under very mild conditions in aqueous media with excellent yields. The efficiency of this reaction is demonstrated by its compatibility with a range of functional groups. Di-ortho-substituted biaryls could be accomplished in 89–99% yields. Moreover, the rigorous exclusion of air or moisture is not required in these transformations.The bis-NHC-Pd complexes prepared in situ can catalyze Suzuki-Miyaura cross-coupling reaction under mild conditions in aqueous media with excellent yields. The efficiency of this reaction is demonstrated by its compatibility with a wide range of functional groups. Di-ortho-substituted biaryls could be accomplished in 89–99% yields. PubDate: 2017-05-30T22:10:48.44626-05:0 DOI: 10.1002/aoc.3896
Authors:Mohsen Nikoorazm; Arash Ghorbani-Choghamarani, Massoud Ghobadi, Shokofeh Massahi Abstract: A palladium S-benzylisothiourea complex was anchored on functionalized MCM-41 (Pd-SBT@MCM-41) and applied as efficient and reusable catalyst for the synthesis of 5-substituted 1H–tetrazoles using [2 + 3] cycloaddition reaction of various organic nitriles with sodium azide (NaN3) in poly(ethylene glycol) (PEG) as green solvent. Also this catalyst was applied as an versatile organometallic catalyst for Suzuki cross-coupling reaction of aryl halides and phenylboronic acid (PhB(OH)2) or sodium tetraphenyl borate (NaB(Ph)4). This nanocatalyst was characterized by thermal gravimetric analysis (TGA), X-ray Diffraction (XRD), scanning electron microscopy (SEM), inductively Coupled Plasma (ICP) and N2 adsorption–desorption isotherms techniques. Recovery of the catalyst is easily achieved by centrifugation for several consecutive runs.A moisture- and air-stable heterogenized Pd-catalyst was synthesized on MCM-41 and identified by TGA, XRD, SEM, ICP and N2 adsorption–desorption isotherms techniques. The application of this catalyst was examined in the synthesis of 5-substituted tetrazoles and C-C coupling reactions. The catalyst was recovered and reused for several runs without significant loss of its catalytic efficiency or palladium leaching. PubDate: 2017-05-30T22:10:32.747729-05: DOI: 10.1002/aoc.3848
Authors:Monika Tyagi; Prateek Tyagi, Sulekh Chandra Abstract: A bioactive Schiff base HL i.e. 2-hydroxy-benzoic acid(3,4-dihydro-2H-naphthalen-1-ylidene)-hydrazide was synthesized by reacting equimolar amount of salicylic acid hydrazide and 1-tetralone. Co(II), Ni(II) and Zn(II) complexes of ligand HL was synthesized in 1:1 and 1:2 molar ratio of metal to ligand. The structure of the synthesized ligand and metal complexes was established by elemental analysis, molar conductance, magnetic susceptibility measurements, electronic, IR and EPR spectral techniques. For determining the thermal stability the TGA has been done. In DFT studies the geometries of Schiff bases and metal complexes were fully optimized with respect to the energy using the 6–31 + g(d,p) basis set. Spectral data reveal that ligand behave uninegative tridentate in ML complexes and uninegative bidentate in ML2 complexes. On the basis of characterization octahedral geometry has been assigned for Co(II) and Ni(II) complexes, while tetrahedral for Zn(II) complexes. Antibacterial activity of the synthesized compounds were evaluated against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Xanthomonas campestris and Pseudomonas aeruginosa and the results revealed that metal complexes show enhanced activity in comparison to free ligand.Co(II), Ni(II) and Zn(II) complexes of 2-hydroxy-benzoic acid(3,4-dihydro-2Hnaphthalen-1-ylidene)-hydrazide have been synthesized and characterized by various spectroscopic techniques. Geometry optimization of the Schiff base and metal complexes was done on Gaussian 09 using the 6–31 + g(d,p) basis set. Spectral data reveal that ligand behave uninegative tridentate in ML complexes and uninegative bidentate in ML2 complexes. Antibacterial activity of the synthesized compounds were evaluated. PubDate: 2017-05-30T22:05:27.612829-05: DOI: 10.1002/aoc.3880
Authors:Aleksandra Sentkowska; Krzysztof Kilian, Maciej Kopeć, Krystyna Pyrzyńska, Łukasz Cheda Abstract: The formation of a complex between Ga(III) and morin (3,5,7,2′,4′-pentahydroxyflavone) was studied. UV–visible, infrared and mass spectroscopies were used to characterize the complex. The stoichiometric ratio for the reaction between metal ion and flavonoid was determined using the methods of Yoe–Jones and Job, which confirmed that a 1:1 Ga–morin complex was formed (estimated binding constant = 2.31 × 104 l mol−1). It was found that the coordination to Ga(III) occurs through the carbonyl oxygen atom and the 3-OH group of the morin molecule. According to developed conditions, complexation reaction with 68Ga was performed and the complex was used to label kidney cancer cells (CAKI-1, CAKI-2, ACHN and 786-O). The knowledge gained from this study should be useful for the development of new radiopharmaceuticals for diagnostic purposes containing 68Ga.The formation of a complex between gallium(III) and morin (3,5,7,2′,4′-pentahydroxyflavone) has been studied. Spectrometric methods were used to characterize the complex. Morin labelled with 68Ga showed good affinity to kidney cancer cells. The results should be useful for the development of new radiopharmaceuticals for molecular imaging containing 68Ga. PubDate: 2017-05-30T22:00:33.900557-05: DOI: 10.1002/aoc.3882
Authors:Asanda C. Matsheku; Marian Y.-H. Chen, Sandra Jordaan, Sharon Prince, Gregory S. Smith, Banothile C.E. Makhubela Abstract: Research aimed at enhancing the efficacy of organometallic complexes against cancer, has shown that attaching bio-active molecules to (metallo)drugs often enhances their biological properties. New salicylaldimine and 2-pyridylimine ligands (L2 and L3), containing a bio-active acridine scaffold, were synthesized and complexed to Rh(III), Ir(III), Ru(II) and Os(II) metal ion centers. The resulting acridine-containing half-sandwich complexes have been characterized fully by elemental analysis, FT-IR and NMR spectroscopy, HR-ESI mass spectrometry as well as single crystal X-ray diffraction, for the Rh(III) N^N bidentate complex [RhCp*Cl(L3)][BPh4]. The antiproliferative activity of the ligands (L2 and L3) and complexes (C1 to C9) were evaluated in vitro against human promyelocytic leukemia cells (HL60) and normal skin fibroblast cells (FG0). The compounds exhibit good activities against HL60 cells and are consistently selective towards cancerous cells over non-tumorous cells. This study demonstrates the potential of such hybrid compounds to target cancer cells specifically. The most active complex, [RhCp*Cl(L2)], exhibited binding to DNA model guanosine-5’-monophosphate (5’-GMP) which suggests a mode of action involving interaction of the complex with 5’-GMP found on DNA backbone.New acridine-conjugated half-sandwich neutral and cationic complexes were synthesized and characterized. These complexes displayed promising cytotoxicity against human promyelocytic leukemia cells (HL60) and a notable selectivity to cancerous cells in comparison to non-tumorous cells (FG0). NMR studies show that the most active complex binds to DNA model guanosine-5’-monophosphate (5’-GMP), thus suggesting that the cytotoxic mechanism involves metal complex interaction with 5’-GMP found on DNA. PubDate: 2017-05-25T04:10:32.074444-05: DOI: 10.1002/aoc.3852
Authors:Cui-Ting Ma; Jiao-Jiao Wang, Ai-Dong Zhao, Qing-Li Wang, Zhan-Hui Zhang Abstract: The application of non-toxic and magnetically separable nano-CuFe2O4 as an efficient catalyst for oxidative homo- and cross-coupling reaction of terminal alkynes is described. A wide range of symmetrical and unsymmetrical 1,3-diynes have been synthesized in moderate to good yields under ambient atmosphere. The nano CuFe2O4 can be recovered with a magnet and reused at least five consecutive cycles with no appreciable loss of its catalytic activity.Magnetically separable nano-CuFe2O4 has been found to be an efficient catalyst for the oxidative homo- and cross-coupling reaction of terminal alkynes. The corresponding symmetrical and unsymmetrical 1,3-diynes are obtained in moderate to good yields under ambient atmosphere. Furthermore, the catalyst can be recovered with a magnet and reused at least five consecutive cycles without appreciable loss of its catalytic activity. PubDate: 2017-05-25T04:00:29.148872-05: DOI: 10.1002/aoc.3888
Authors:A.M. Wrobel; P. Uznanski, A. Walkiewicz-Pietrzykowska, K. Jankowski Abstract: Amorphous silicon carbonitride (a-SiCN) films were produced by remote nitrogen plasma chemical vapour deposition (RP-CVD) from bis(dimethylamino)methylsilane precursor. The effect of substrate temperature (TS) on the kinetics of RP-CVD, chemical structure, surface morphology and some properties of the resulting films is reported. The TS dependence of film growth rate implies that RP-CVD is an adsorption-controlled process. Fourier transform infrared spectroscopic examination revealed that an increase in TS from 30 to 400°C involves the elimination of organic moieties from the film and the formation of Si─C and Si─N network structure. The films were characterized in terms of their surface roughness and basic physical and optical properties, such as density and refractive index, respectively. Reasonably good relationships between the structural parameters represented by relative integrated intensity of infrared absorption bands from the Si─C and Si─N bonds (controlled by TS) and the film properties are determined. Due to their small surface roughness, high density and high refractive index, the a-SiCN films produced at TS ≥ 350°C would seem to be useful protective coatings for metals and optical devices.Amorphous silicon carbonitride (a-SiCN) films deposited from bis(dimethylamino)methylsilane precursor are characterized in terms of effect of deposition temperature (TS) on growth kinetics, chemical structure, surface morphology and other properties. Film density is correlated with the content of Si─C and Si─N bonds. There is a transformation of a-SiCN films from low-crosslink-density polymeric-like materials (TS ≤ 200°C) to high-crosslink-density ceramic-like materials (TS > 200°C). PubDate: 2017-05-25T03:55:53.874716-05: DOI: 10.1002/aoc.3871
Authors:Zeng-Xiu Sun; Ling-Yang Wang, Yan-Tuan Li, Zhi-Yong Wu, Cui-Wei Yan Abstract: A new oxamido-bridged dicopper(II) complex formulated as [Cu2(ndpox)(bpy)(CH3OH)2]- (ClO4), where H3ndpox is N-(2-hydroxy-5-nitrophenyl)-N′-[3-(diethylamino)propyl]oxamide; and bpy represents 2,2′-bipyridine, was synthesized and structurally characterized using X-ray single-crystal diffraction and other methods. In the molecule, the endo- and the exo-copper(II) ions bridged by the cis-ndpox3− ligand are in {N3O2} and {N2O3} square- pyramidal environments, respectively. There is a three-dimensional hydrogen bonding network dominated by O-H···O and C-H···O interactions in the crystal. The reactivity toward DNA/protein bovine serum albumin (BSA) revealed that the complex could interact with herring sperm DNA (HS-DNA) through the intercalation mode, and effectively quench the intrinsic fluorescence of BSA via a static process. Cytotoxicity studies suggest that the complex displays selective cancer cell antiproliferative activity. The present investigation confirmed that the combined effects of both electron-withdrawing and hydrophobic groups on the bridging ligand in the dicopper(II) complex systems can increase DNA/BSA-binding ability and in vitro anticancer activity.A new dicopper(II) complex was synthesized and structurally characterized. The present study highlighted that the synergistic effects of both electron-withdrawing and hydrophobic groups on the asymmetic N,N′-bis(substituted)oxamide bridging ligand in the dicopper(II) complex systems can increase DNA/BSA-binding ability and in vitro anticancer activity. PubDate: 2017-05-25T03:45:54.039508-05: DOI: 10.1002/aoc.3835
Authors:Mostafa M. Amini; Ezzatollah Najafi, Hamid Saeidian, Elham Mohammadi, Shiva Mosavi Shahabi, Seik Weng Ng Abstract: To investigate the effect of pseudo-halogen groups on the structure and optical properties of diorganotin(IV) coordination compounds the reaction of dimethyltin diisothiocyanate and dimethyltin dichloride with 1,2,3,4-tetra- (4-pyridyl)-butane (TPB) were studied. The results of spectroscopic data and structural analyses of prepared compounds showed that the reaction of Me2SnCl2 with TPB ligand leads to the formation of a 2D organotin(IV) coordination polymer, while the replacement of chloride ions with thiocyanate ions as pseudohalogen groups in the structure of Me2SnCl2 results in the development of a salt with an anion complex and a dimeric stannoxane as a side product. The results showed that the use of pseudo-halogen groups instead of halogen groups in the structure of diorganotin(IV) dihalogen compounds could be as a suitable factor in the control of the structure of diorganotin(IV) coordination compounds. The investigation of optical properties of prepared compounds demonstrated that the use of pseudo-halogen groups in the structure of diorganotin(IV) coordination compounds have an influence on their photoluminescence behavior.The effect of pseudo-halogen groups on the structure and optical properties of diorganotin(IV) coordination were investigated. Structural analyses showed that the reaction of Me2SnCl2 with 1,2,3,4-tetra- (4-pyridyl)-butane ligand leads to the formation of a 2D organotin(IV) coordination polymer, while the replacement of chloride ions with thiocyanate ions in the structure of Me2SnCl2 results to salt formation. Optical properties studies showed that the use of pseudo-halogen groups in the structure of diorganotin(IV) coordination compounds have an influence on their photoluminescence behavior. PubDate: 2017-05-24T01:45:43.280794-05: DOI: 10.1002/aoc.3884
Authors:Saeed Baghery; Mohammad Ali Zolfigol, Romana Schirhagl, Masoumeh Hasani, Marc C.A. Stuart, Andreas Nagl Abstract: Four novel magnetic nanoparticle catalysts with urea or urethane moieties are reported. The silica-coated magnetic nanoparticles were simply functionalized via addition of 3-(triethoxysilyl)propylisocyanate (TESPIC), amine or amino alcohol. TESPIC with dual labile functional groups was used as a suitable precursor for the synthesis of urethane-based catalysts. The newly synthesized catalysts were fully characterized using a variety of techniques. These functionalized magnetic nanoparticles were used as reusable catalysts in the Strecker synthesis of α-aminonitrile derivatives under solvent-free conditions at 50 °C.Four novel biological-based magnetic nanoparticle catalysts with urea or urethane moieties were synthesized via reaction of 3-(triethoxysilyl)propylisocyanate, amine or amino alcohol and silica-coated magnetic cores. Their catalytic application was also studied in the Strecker synthesis of α-aminonitrile derivatives. PubDate: 2017-05-24T01:45:29.471225-05: DOI: 10.1002/aoc.3883
Authors:Sara Sobhani; Fatemeh Khakzad Abstract: A novel hydrophobic copper complex supported on γ-Fe2O3 is synthesized and characterized by different methods such as FT-IR, XRD, TEM, SEM, TGA, VSM, ICP and CHN analysis. It was used as a magnetically recyclable heterogeneous catalyst for the efficient synthesis of α-aminophosphonates via a one-pot three-component reaction under solvent-free conditions. The present catalytic system worked extremely well for the synthesis of α-aminophosphonates even up to five subsequent trails without significant loss of its catalytic activity or copper leaching. The TEM image and FT-IR spectrum of the catalyst after five times recovery showed that the structure of the catalyst was stable under the reaction conditions with no change being observed. The strong magnetic properties of the reused catalyst were revealed by complete and easy attraction using an external magnet and also by VSM curve. This work represents the first and unique example of a hydrophobic copper complex for catalysis in water generating reactions.A novel hydrophobic copper complex supported on γ-Fe2O3 is synthesized and characterized by different methods such as FT-IR, XRD, TEM, SEM, TGA, VSM, ICP and CHN analysis. It was used as a magnetically recyclable heterogeneous catalyst for the efficient synthesis of α-aminophosphonates via a one-pot three-component reaction under solvent-free conditions. PubDate: 2017-05-24T01:40:33.845015-05: DOI: 10.1002/aoc.3877
Authors:Mohamed Gaber; Abdalla M. Khedr, Mohsen Elsharkawy Abstract: New seven complexes of N1,N6-bis((2-hydroxynaphthalin-1-yl)methinyl))adipohydrazone (H2L) with MnCl2•4H2O, CoCl2•6H2O, NiCl2•6H2O, CuCl2•2H2O, Cu(NO3)2•3H2O, CuSO4•5H2O, and Cu(OAc)2•2H2O have been prepared and characterized by the aid of elemental and thermal analyses, spectra (FT-IR, 1H NMR, MS, UV-Vis, ESR, X-ray powder diffraction), molar conductance and magnetic moment measurements. The XRD results unambiguously confirmed the nano-sized particles of the complexes. The results showed that H2L behaves as dibasic tetra-dentate ligand towards the metal ions of interest. The low molar conductance values revealed the non-electrolytic nature for the chelates. The magnetic moment data, UV-Vis and ESR spectra denoted the formation of octahedral geometries for Mn(II) and Ni(II) complexes, whereas Co(II), Cu(II) complexes exhibited tetrahedral arrangement. The activation parameters for the thermal decomposition stages were calculated from TGA curves using Coats-Redfern and Horowitz–Metzger methods. The obtained data were confirmed by 3-D molecular modeling of the ligand and some complexes. The investigated compounds were screened for their antimicrobial activities against different types of organisms and antitumor activities towards human liver Carcinoma (HEPG2) cell to access their potential chemotherapeutic use. The free ligand (H2L) exhibited a weak inhibition of cell viability with IC50 of 11.80 μg/ml, complexes 4, 6 and 7 showed a moderate activity with IC50 of 5.56, 7.71 and 5.67 μg/ml, whereas complexes 1, 2, 3, and 5 displayed a strong anticancer activity with IC50 of 4.65, 3.97, 3.30 and 4.84 μg/ml, compared with IC50 value of 4.73 μg/ml for the doxorubicin (standard cytotoxin drug).In-vitro cytotoxicity of N1,N6-bis((2-hydroxynaphthalin-1-yl)methinyl))adipohydrazone (ligand) and its complexes 1–7 against human liver Carcinoma cell line (HEPG2). PubDate: 2017-05-23T00:00:32.306525-05: DOI: 10.1002/aoc.3885
Authors:S. Jayakumar; D. Mahendiran, V. Viswanathan, D. Velmurugan, A. Kalilur Rahiman Abstract: Three new heteroscorpionate ligands, (2-hydroxyphenyl)bis(imidazol-1-yl)methane (HL1), (4-diethylamino-2-hydroxyphenyl)bis(imidazol-1-yl)methane (HL2) and (5-bromo-2-hydroxyphenyl)bis(imidazol-1-yl)methane (HL3), and their heteroleptic copper(II) complexes of the type [Cu(L1–3)diimine]ClO4 (1–6; where diimine =2,2′-bipyridyl or 1,10-phenanthroline) have been synthesized and characterized using spectroscopic methods. The molecular structure of ligand HL1 was determined by single-crystal X-ray diffraction. UV–visible, electron paramagnetic resonance and theoretical studies suggest a distorted square pyramidal geometry around copper(II) ion. Analyses of highest occupied and lowest unoccupied molecular orbitals have been used to explain the charge transfer taking place within the complexes. The antioxidant activities of the heteroscorpionate ligands and their heteroleptic copper(II) complexes were determined using ABTS, DPPH and H2O2 free radical scavenging assays with respect to standard antioxidant ascorbic acid. In molecular docking studies, the complexes showed π–π, hydrogen bonding, van der Waals and electrostatic interactions with fibroblast growth factor receptor kinase. In vitro cytotoxicity activities of ligands and copper(II) complexes were examined on human breast adenocarcinoma (MCF-7), cervical (HeLa) and lung (A549) cancer cell lines and normal human dermal fibroblast cell line using MTT assay. Complex 4 exhibited higher anticancer activity than the other complexes against all three cancer lines, being more potent than the standard drug cisplatin.Six heteroscorpionate-based heteroleptic copper(II) complexes have been synthesized and characterized. The antioxidant activity was performed using three different methods. In vitro cytotoxicity was performed against three cancerous and one normal cell lines by MTT assay. Molecular docking study was performed with FGFR kinase. The complex containing electron-releasing substituent (─N(C2H5)2) and extended aromaticity exhibit highest biological activity. PubDate: 2017-05-22T23:15:39.323831-05: DOI: 10.1002/aoc.3809
Authors:Sima Porhemmat; Alireza Rezvani, Mehrorang Ghaedi, Arash Asfaram, Alireza Goudarzi Abstract: Present research describe applicability of tin oxide hydroxide nanoparticles loaded on activated carbon (Sn6O4 (OH)4-NPs-AC) which recognized via by Field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) for the rapid simultaneous removal of Methyl orange (MB) and methylene blue (MB) in mixture in the presence of ultrasonic wave. The central composite design (CCD) pattern as branch of response surface methodology (RSM) give useful information about influence of five most important operating variables is separate and combination nature namely pH (4.0–8.0), initial MO (8–24 mg L−1) and MB concentration (4–12 mg l−1), sonication time (2–6 min) and adsorbent mass (0.01–0.03 g) on the ultrasound under study dyes assisted adsorption. After surveying the experiment data and finding regression analysis correspond to experimental data, mathematical model and equation was constructed and derived which applied for optimizing ultrasound assisted adsorption and revel serious dependency of response to variables like adsorbent mass and sonication time s. F values of 114.5 and 165.5, coefficient of determination (R2) of 0.9978 and 0.9985, adjusted-R2 of 0.9891 and 0.9925, adequate precision (AP) of 39.11 and 40.23, coefficient of variation (CV) of 0.653 and 1.988% for MB and MO respectively, implied the satisfactory adjustment of the quadratic model. Based on CCD, the optimum conditions was set as pH of 6.0; 0.02 g adsorbent; 20 and 12 mg l−1 of MO and MB concentration and 2 min sonication time. The predicted removal of MO and MB in binary system were 98.19 and 98.02% which was good agreement with their experimental R% MO and MB value of 98.00% for both at optimum condition. The equilibrium data has good agreement with Langmuir with maximum monolayer adsorption capacity of 30.90 and 25.70 mg g−1 for MO and MB respectively. Investigation of time dependency of adsorption data revel more applicability pseudo-second order in cooperation with intraparticle diffusion description of the mechanism and adsorption rate.Sn6O4 (OH)4-NPs-AC as a novel adsorbent were used for simultaneous removal of MO and MB.Significant variables were investigated using the response surface methodology.The dyes adsorption data were best followed by Langmuir and pseudo-second order models. PubDate: 2017-05-19T05:58:02.323266-05: DOI: 10.1002/aoc.3860
Authors:Jing Huang; Weigang Ding, Jiali Cai Abstract: Chiral Jacobsen's catalysts grafted onto alkoxyl-modified ZPS-PVPA exhibit excellent activities (conv%, up to 96; sele%, up to 96; ee%, up to >99) in the asymmetric epoxidations of unfunctionalized olefins. The superior stabilities and the comfortable dispositions in large-scale reactions contribute to the potential applications in industry.The immobilized Jacobsen's catalysts onto ZPS-PVPA indicate superior catalytic performance both for experimental scale and for large-scale reactions. PubDate: 2017-05-19T05:51:16.800963-05: DOI: 10.1002/aoc.3861
Authors:Divya Hegde; Suneel Dodamani, Vijay Kumbar, Sunil Jalalpure, Kalagouda B. Gudasi Abstract: A novel tridentate chelating ligand, Ethyl 2-(2-(2-chlorobenzoyl)hydrazono)propanoate and its late transition metal complexes were synthesized, characterized and evaluated for anticancer behavior. The structures were elucidated with the help of elemental analyses, spectral (vibrational, electronic, NMR and mass) and thermo-gravimetric techniques. Single crystal X-ray crystallographic studies of the ligand suggest an orthorhombic lattice structure with Pna21 space group. The interaction of ligand and complexes with DNA (CT-DNA) has been extensively studied using absorption, emission, viscosity and thermal denaturation studies with E. coli DNA. The DNA cleavage ability of ligand and metal complexes was tested using plasmid pBR322 DNA by gel electrophoresis method. The ligand and its copper complex have been evaluated for their in vitro anticancer activity against human cancer cells of different origin such as KB (Oral), A431 (Skin), Mia-Pa-Ca (Pancreases), K-549 (Lung), K-562 (Leukemia), MCF-7 (Breast) and VERO by MTT assay and the apoptosis assay was carried out with acridine orange/ethidium bromide (AO/EB) staining method. The studies suggest that ligand and copper complex exhibit significant cytotoxic activity on KB, MCF-7, A-431, Mia-Pa-Ca-2 an d A-549 cell lines compared to K-562 and VERO cell lines.A novel tridentate chelating ligand, Ethyl 2-(2-(2-chlorobenzoyl)hydrazono)propanoate and its late transition metal complexes were synthesized, characterized and evaluated for their DNA interaction and anticancer behavior by MTT assay and the apoptosis assay was carried out with acridine orange/ethidium bromide (AO/EB) staining method. PubDate: 2017-05-16T03:35:53.806502-05: DOI: 10.1002/aoc.3851
Authors:Ehsan Solaymani; Mehrorang Ghaedi, Hajir Karimi, Mohammad Hossein Ahmadi Azqhandi, Arash Asfaram Abstract: In this work Random Forest (RF) and Response surface methodology (RSM) were used to model and predict the efficiency of malachite green removal from aqueous solution by ultrasound-assisted adsorption onto the silver hydroxide nanoparticles loaded on activated carbon (AgOH-NPs-AC). The prepared nanoparticles were characterized by SEM, FTIR, XRD and TEM. The parameters such as pH, initial MG concentration, sonication time and adsorbent dosage involved in the adsorption process were set within the ranges 2.0–10, 4–20 mg L−1, 2–6 min and 0.005–0.025 g, respectively. The performance of the RF and CCD models for the description of experimental data was evaluated in terms of the coefficient of determination (R2), the root mean squared error (RMSE), mean absolute error (MAE) and absolute average deviation (AAD). The obtained results showed that the RF model outperformed in comparison to classical statistical model for modeling the process of dye adsorption. Desirability function approach (DFA) and Genetic algorithm (GA) combined central composite design (CCD) as global optimization technique were used for simultaneous optimization of effective factors. GA and DFA were revealed that 20 mg L−1 MG by 0.025 g AgOH-NPs-AC at pH = 8.0 and sonication time for 6 min with adsorption capacity 40.98 and 41.99 mg g−1 can be removed, respectively. The equilibrium adsorption data were analyzed by Langmuir Freundlich, Temkin and Dubinin-Radushkevich isotherm models. The best fit to the data was obtained from the Langmuir model. Meanwhile, the maximum adsorption capacity for MG by 0.01, 0.02 and 0.025 g of AgOH-NPs-AC was estimated 57.143, 42.735 and 40.980 mg g−1, respectively. Analysis of experimental adsorption data to various kinetic models shows the applicability of the second-order equation model. The variable importance principle also shows that RF give maximum importance to sonication time for removal of MG.In this work, activated carbon modified with AgOH-NPs-AC was used as an efficient adsorbent for the MG removal from aqueous solution. Also, the adsorption process was optimized using RSM and RF. The variable importance principle shows that RF gives maximum importance to sonication time for removal of MG. It was seen that MG adsorption on AgOH-NPs-AC follows the pseudo second-order and Elovich models. PubDate: 2017-05-16T03:30:44.17801-05:0 DOI: 10.1002/aoc.3857
Authors:Jegathalaprathaban Rajesh; Mookkandi Palsamy Kesavan, Srinivasan Ayyanaar, Kesavan Karthikeyan, Gurusamy Rajagopal, Periyakaruppan Athappan Abstract: Four new platinum(II) complexes [Pt(dpen)(bpy)](ClO4)2 (1), [Pt(dpen)(phen)](ClO4)2 (2), [Pt(dpen)(dpq)](ClO4)2 (3) and [Pt(dpen)(dppz)](ClO4)2 (4) comprising of different N,N-donor ligands, viz., 2,2′-bipyridine (bpy), 1,l0-phenanthroline (phen), dipyridoquinoxaline (dpq), dipyrido-[3,2-d:2¢,3¢-f–phenazine] (dppz), and chiral ancillary ligand 1R,2R-1,2-diphenylethylenediamine (dpen) have been synthesized and characterized. The interaction of these complexes 1–4 with calf-thymus DNA (CT-DNA) has been explored using absorption, circular dichroism spectral and cyclic voltammetric studies. The absorption spectrum of complex 4 with dppz ligand exhibits a major red shift with an overall hypochromic as well as a hyperchromic effect in the presence of DNA, other complexes (1–3) show only hypochromism. From these absorption spectral studies, the intercalative ability of the complexes follows the order as, 4 > 3 > 2 > 1, which is further confirmed by CD and cyclic voltammetry measurements. CD spectral studies show that DNA becomes more A-like upon interaction with the complexes 1 & 2 but the complexes 3 & 4 bring about B-form to Z- form DNA conformational transition. The DNA cleavage study of these Pt(II) complexes 1–4 carried out by gel electrophoresis revealed that complexes 1–4 can cleave super coiled (SC) pUC18 DNA efficiently into open circular form (form II) under hydrolytic and oxidative conditions.New Pt(II) complexes 1-4 are prepared and characterized using spectral techniques. Complex 4 with dppz ligand and has effective DNA binding behavior than others. Pt(II) complexes 1-4 cleaved super coiled DNA under hydrolytic as well as oxidative conditions. PubDate: 2017-05-16T03:26:28.157102-05: DOI: 10.1002/aoc.3868
Authors:Jafar Afshani; Alireza Badiei, Mehdi Karimi, Negar Lashgari, Ghodsi Mohammadi Ziarani Abstract: A novel organic–inorganic silica-based fluorescent probe was designed, synthesized and characterized by different techniques such as XRD, BET, TGA, and FT-IR. The fluorescence properties of the probe were studied in the presence of a variety of metal-ions in water. The results revealed that various metal-ions negligibly vary the emission intensity of the probe except for Hg2+, which quenched the intensity dramatically. The selectivity of the probe toward Hg2+ ion was further investigated in the presence of common competing metal-ions and the results demonstrated the high selectivity of the probe toward Hg2+ ion. The fluorescence emission of the probe was also studied as a function of the concentration of Hg2+ ion. A nanomolar limit of detection was estimated for Hg2+, indicating a high sensitivity. Furthermore, the probe showed INHIBIT-type logic behavior with Hg2+ and H+ as inputs. Also, the optimum pH range was studied in addition to reversibility and real world applicability of the probe.A novel fluorescent probe based on functionalization of SBA-15 with a Schiff base was synthesized and displayed a high selectivity for Hg2+ over a variety of metal ions in water with a nanomolar limit of detection. Furthermore, the probe showed INHIBIT- type logic behavior with Hg2+ and H+ as inputs. PubDate: 2017-05-16T03:25:52.699033-05: DOI: 10.1002/aoc.3856
Authors:Lei Chen; Wei Teng, Xin-Le Geng, Yi-Fan Zhu, Yong-Hong Guan, Xiaohui Fan Abstract: A simple AlCl3-catalyzed condensation/cyclization cascade process between aldehydes and sulfonamide is reported, in which two new bonds and one five-membered ring are simultaneously formed with water as the byproduct. This method provides a rapid access to indenamine and 9-aminofluorene derivatives. Additionally, these products can be transformed into corresponding indanones and fluorenones under the developed conditions.A simple two-component condensation/cyclization cascade process to indene and fluorene derivatives was disclosed, in which two new bonds and one five-membered ring are simultaneously formed with water as the byproduct. PubDate: 2017-05-16T03:15:34.130495-05: DOI: 10.1002/aoc.3863
Authors:Zahra Nasresfahani; Mohammad Zaman Kassaee, Esmaiel Eidi Abstract: We report the synthesis of ionic liquid-functionalized mesoporous silica nanoparticles ([pmim]FeCl4/MSNs) via a method of post-grafting on parent MSNs. This hybrid material was characterized using scanning and transmission electron microscopies, energy-dispersive X-ray spectroscopy, nitrogen adsorption–desorption analysis, Fourier transform infrared spectroscopy, powder X-ray diffraction and thermal analyses. The material was utilized as an efficient heterogeneous catalyst for the synthesis of N,N′-diaryl-substituted formamidines through the reaction of triethyl orthoformate with arylamines under solvent-free conditions. The catalyst was recovered easily and reused several times without significant loss of its catalytic activity.The catalytic performance of nanoparticles ([pmim]FeCl4/MSNs) is confirmed for the synthesis of N,N′-diaryl-substituted formamidines through the reaction of triethyl orthoformate with arylamines. PubDate: 2017-05-16T02:55:40.228732-05: DOI: 10.1002/aoc.3800
Authors:Dario Drommi; Carmela Grazia Arena Abstract: The design and synthesis of three new C2-symmetric chiral diphosphoramidite ligands starting from simple and cheap building blocks have been developed. Rhodium(I) cationic complexes bearing these chelate ligands have been prepared and applied in asymmetric hydrogenation of model olefins. A rhodium complex with a diphosphoramidite containing a chiral diamine configurationally stable and two fluxional chiral biphenyl units gave higher enantioselectivity with increasing hydrogen pressure (87% ee) in the hydrogenation of dimethyl itaconate.The design and synthesis if three new C2-symmetric chiral diphosphoramidite ligands starting from simple and cheap building blocks have been developed. Rhodium(I) cationic complexes bearing these chelate ligands have been prepared and applied in asymmetric hydrogenation of model olefins. A rhodium complex with a diphosphoramidite containing a chiral diamine configurationally stable and two fluxional chiral biphenyl units gave higher entantioselectivity with increasing hydrogen pressure (87% ee) in the hydrogenation of dimethyl itaconate. PubDate: 2017-05-16T02:40:35.835051-05: DOI: 10.1002/aoc.3837
Authors:Jabir H. Al-Fahemi; Fawaz A. Saad, Nashwa M. El-Metwaly, Thoraya A. Farghaly, Marwa G. Elghalban, Kamel A. Saleh, Gamil A. Al-Hazmi Abstract: New synthesis of Co(II), Cu(II), Hg(II), UO2(II) and Pb(II) binuclear nanometric complexes derived from multi-donor ligand is reported. Structural and molecular formulae of all isolated complexes were established. Bi-negative hexa-dentate mode of ligand was proposed for the two central atoms in all complexes. Infrared, UV–visible, magnetic moments, electron paramagnetic resonance, thermogravimetric analysis and elemental analysis were used to build all structural formulae. X-ray diffraction and scanning electron microscopy were used to determine the morphological features of the compounds and to compute particle sizes. Theoretical computations were implemented to support the proposed formulae. Kinetic study was executed over suitable stages to clarify the comparative stabilities. The DFT/B3LYP method, using the Gaussian 09 program, was utilized for optimizing the distribution of atoms over all compounds except the UO22+ complex. This exclusion refers to an inability to find a suitable method. Significant parameters were estimated using frontier energies (highest occupied and lowest unoccupied molecular orbitals) and data log file. A quantitative structure–activity relationship study applying HyperChem was executed for the organic compound tautomer forms to give a significant view about their biological character. AutoDock tools 4.2 were used to investigate the biological trend of organic compounds (keto and enol) against three types of proteins. The types were chosen related to in vitro investigation: breast, prostate and liver carcinoma proteins. IC50 values indicated insignificant inhibition activity towards all carcinoma cell lines under investigation, except for the Hg(II) complex which displayed distinct activity against breast carcinoma compared with reference drug (doxorubicin).The bi-negative hexa-dentate ligand was proposed with all metal ions. Essential parameters were extracted to predict biological features for most stable stereo structures through molecular modeling and docking studies. A poor impact was recorded for the complexes against all three utilized carcinoma cell lines, except for the Hg(II) complex, which displayed a promising result against breast carcinoma PubDate: 2017-05-16T02:35:58.352595-05: DOI: 10.1002/aoc.3787
Authors:Meghdad Karimi; Taraneh Hajiashrafi, Akbar Heydari, Alireza Azhdari Tehrani Abstract: A terbium–organic framework (Tb-MOF) was prepared using a previously reported procedure. Tb-MOF was characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, powder X-ray diffraction and surface area analysis. Tb-MOF was employed as a heterogeneous Lewis acid catalyst for the synthesis of β-aminoalcohols. Also, the effect of ultrasonic irradiation was examined in the catalytic aminolysis of styrene oxide. The reaction conditions were optimized by variation of reaction time, catalyst concentration and solvent. A variety of β-aminoalcohols were synthesized and characterized. The Tb-MOF catalyst showed excellent selectivity and high yield for these transformations.A terbium–organic framework (Tb-MOF) was prepared, characterized and employed as a heterogeneous Lewis acid catalyst for the synthesis of β-aminoalcohols. PubDate: 2017-05-16T02:35:34.464623-05: DOI: 10.1002/aoc.3866
Authors:Arash Ghorbani-Choghamarani; Hossein Rabiei, Fatemeh Arghand Abstract: In this paper, we report a simple, facile and efficient method for the synthesis of Fe3O4/SiO2-DTZ-Pd. The immobilized palladium was an efficient catalyst without addition of phosphine ligands for Stille, Heck and N-arylation reactions. This method has some advantages such as high yields and easy work up of products. In addition, the catalyst can be recovered using a magnet and reused several times without significant loss of its catalytic activity. This catalyst was characterized by various physico-chemical techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and inductively coupled plasma (ICP).An efficient palladium dithizone complex was immobilized on Fe3O4 magnetic nanoparticles and characterized by different techniques. The catalytic activity of this catalyst was examined in the C-C and C-N coupling reactions. PubDate: 2017-05-16T02:25:35.71828-05:0 DOI: 10.1002/aoc.3839
Authors:Nazan Kaloğlu; İlknur Özdemir, Selami Günal, İsmail Özdemir Abstract: A series of novel benzimidazolium bromides containing bulky 3,5-di-tert-butyl group were synthesized in high yields as N-heterocyclic carbene (NHC) ligands. These NHC ligands were metallated with Ag2O under moderate conditions to give novel silver–NHC complexes. The structures of all compounds were characterized using 1H NMR, 13CNMR, infrared and elemental analysis techniques, which supported the proposed structures. The silver–NHC complexes were screened for their in vitro antimicrobial activities against the standard bacterial strains Enterococcus faecalis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa and the fungal strains Candida albicans and C. tropicalis. The results showed that most of the silver–NHC complexes inhibited the growth of all bacterial strains and fungal strains and were found to display effective antimicrobial activity against different microorganisms.Novel benzimidazolium bromides and their silver–NHC complexes were synthesized. These complexes were tested against Gram-negative bacteria (E. coli and P. aeruginosa), Gram-positive bacteria (E. faecalis and S. aureus) and fungi (C. albicans and C. tropicalis). The result showed that most of the silver–NHC complexes had good activities against the various microorganisms. PubDate: 2017-05-15T06:26:42.422327-05: DOI: 10.1002/aoc.3803
Authors:Ye Yuan; Yu Xie, Dandan Song, Cheng Zeng, Somboon Chaemchuen, Cheng Chen, Francis Verpoort Abstract: A series of N-heterocyclic carbene (NHC)/Ag systems were developed for the carboxylative assembly of propargylic alcohols and carbon dioxide (CO2). With the catalysis of these catalytic systems, a variety of target α-alkylidene cyclic carbonates could be obtained smoothly under atmospheric CO2 pressure in straightforward one-pot processes. Particularly, these reactions could be performed without any stoichiometric addition of bases or additives. Further mechanistic investigation reveals that the excellent activities are attributed to the effective activations of CO2 accomplished by the NHCs via the formation of the NHC-CO2 adducts.A series of N-heterocyclic carbene (NHC)/Ag systems were developed for the carboxylative assembly of propargylic alcohols and carbon dioxide (CO2). Desired products were obtained in one-pot processes under atmospheric CO2 pressure without additives and bases. The excellent activities are attributed to the efficient activations of CO2 via a NHC-CO2 adducts. PubDate: 2017-05-15T06:16:17.621775-05: DOI: 10.1002/aoc.3867
Authors:Shikha Dubey; Yogesh Chandra Sharma Abstract: The present study deals with the synthesis of CuO-NPs via green route and investigated its application for removal of Cr(VI) from aqueous solutions. The experimental parameters were optimized through Box–Behnken Design (BBD) of response surface methodology for the optimum response. The adsorption equilibrium data was well fitted to Freundlich isotherm model and the kinetics was explained through pseudo-second-order kinetic model. The overall process was feasible, spontaneous and exothermic. Linear approach for analysing the isotherm as well as kinetic parameters was found more appropriate than the non-linear approach. The adsorbent was successfully regenerated and reused up to five consecutive cycles without significant loss in removal capacity. The experimental results exhibited that CuO-NPs can be a good alternative for Cr(VI) removal from aqueous solutions.The CuO-Nano particles, synthesized via green route were used for the removal of Cr(VI) from aqueous solutions. Process of removal was optimized by response surface methodology. The data fitted Freundlich isotherm model and the process of removal followed second order kinetics. Linear approach for analysing the isotherm as well as kinetic parameters was found more appropriate than the non-linear approach. The adsorbent was successfully regenerated and reused up to five cycles. CuO-NPs can be a good alternative for Cr(VI) removal from aqueous solutions. PubDate: 2017-05-15T06:11:54.947156-05: DOI: 10.1002/aoc.3849
Authors:Seyyed Javad Sabounchei; Asieh Sedghi, Ali Hashemi, Marjan Hosseinzadeh, Mehdi Bayat, Robert W. Gable Abstract: The new unsymmetrical phosphonium salts [Ph2PCH2PPh2CH2C(O)C6H4R]Br (R= m-Br (S1) and p-CN (S2)) were synthesized in the reaction of 1,1-bis(diphenylphosphino)methane (dppm) and BrCH2C(O)C6H4R (R= m-Br and p-CN) ketones, respectively. Further treatment with NEt3 gave the α-keto stabilized phosphorus ylides Ph2PCH2PPh2C(H)C(O)C6H4R (R= m-Br (Y1) and p-CN (Y2)). These ligands were reacted with [MCl2(cod)] (M= Pd and Pt; cod= 1,5-cyclooctadiene) to give the pallada- and platinacycle complexes [MCl2(Ph2PCH2PPh2C(H)C(O)C6H4R)] (M= Pd, R= m-Br (3); R= p-CN (4) and M= Pt, R= m-Br (5); R= p-CN (6)). Cyclic voltammetry, elemental analysis, IR and NMR (1H, 13C and 31P) spectroscopic methods were used for characterization of the obtained compounds. Further, the structure of complexes 3 and 4 were characterized crystallographically. Palladacycles 3 and 4 were proved to be excellent catalysts for the Suzuki-Miyaura coupling reactions of various aryl chlorides and arylboronic acids in mixed DMF/H2O media. Also, the bonding situations between two interacted fragments [PtCl2] and Y1 and Y2 ligands in platinacycles 5 and 6 were investigated based on DFT method by using NBO, EDA and ETS-NOCV analysis.We report the synthesis and characterization of new pallada- and platinacycle complexes [MCl2(Ph2PCH2PPh2C(H)C(O)C6H4R)] (M= Pd and Pt, R = m-Br and p-CN) and application of Pd(II) complexes as catalyst in Suzuki-Miyaura coupling reaction. PubDate: 2017-05-12T00:29:36.471155-05: DOI: 10.1002/aoc.3850
Authors:Dariush Saberi; Samira Poorsadeghi Abstract: Synthesis of enol carbamates was achieved via nickel-catalyzed oxidative coupling of formamides with 1,3-dicarbonyl compounds in the presence of tert-butyl hydroperoxide at 40 °C. Various derivatives of enol carbamates were synthesized by this method in good to excellent yields.C-O bond formation between formamides and 1,3-dicarbonyls toward the synthesis of the corresponding carbamates in the presence of NiCl2 as a new, cheap and effectice catalyst. PubDate: 2017-05-12T00:24:36.565823-05: DOI: 10.1002/aoc.3855
Authors:Lei Sun; Hui Chen, Changneng Chen Abstract: Reactions of manganese benzoate dihydrate and lanthanide nitrate hexahydrate with 2-(hydroxymethyl)pyridine (hmpH) as ligand in the mixture solutions of acetonitrile and ethanol according to different molar ratios of NEt3 generated two kinds of Mn-Ln compounds [MnIII4LaIII2(O)2(hmp)7(PhCO2)2(NO3)5] ·5H2O (1) and [MnIII2GdIII2(hmp)6(PhCO2)4(NO3)2] ·3CH3CN·3C2H5OH·2H2O (2). By comparison of the two compounds, there exist considerable effects of reaction alkalinity on the structures and magnetic properties of products. Compound 1 possesses a core of [MnIII4LaIII2(μ4-O)(μ3-O)(μ3-OR)(μ2-O)7]2−, which comprises three face-sharing defected cubane units. The core topology represents a new core type of Mn-Ln clusters. Compound 2 has a planar-butterfly structure. The solid-state dc magnetic susceptibility analyses indicate the antiferromagnetic interactions within compound 1 and ferromagnetic interactions within compound 2. Compound 1 has an S = 0 ground state, while compound 2 possesses an S = 11 ground state, fitting of the dc data for the tetranuclear Mn2Gd2 with the Magpack program gives parameters of JMn-Mn = 3.11 cm−1, JMn-Gd = 0.02 cm—1 and g = 1.96.The hexanuclear and tetranuclear compounds were synthesized by the same reaction except alkalinity reaction condition. By comparsion of the two compounds, there exist considerable effects of alkalinity on the structures and magnetic properties of compounds. PubDate: 2017-05-11T23:58:53.983992-05: DOI: 10.1002/aoc.3846
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