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991.
Rahman Bikas Massomeh Ghorbanloo Roya Sasani Ingo Pantenburg Gerd Meyer 《Journal of Coordination Chemistry》2017,70(5):819-830
The reaction between tridentate NNO donor hydrazone ligands, (E)-2-cyano-N′-(phenyl(pyridin-2-yl)methylene)acetohydrazide (HL1) and (E)-2-cyano-N′-(1-(pyridin-2-yl)ethylidene)acetohydrazide (HL2), with MnCl2·4H2O in methanol resulted in [Mn(HL1)Cl2(CH3OH)] (1) and [Mn(HL2)Cl2(CH3OH)] (2). Molecular structures of the complexes were determined by single-crystal X-ray diffraction. All of the investigated compounds were further characterized by elemental analysis, FT-IR, TGA, and UV–Vis spectroscopy. These complexes were used as catalysts for olefin oxidation in the presence of tert-butylhydroperoxide (TBHP) as an oxidant. Under similar experimental conditions with equal manganese loading, the presence of [Mn(HL2)Cl2(CH3OH)] (2) resulted in higher conversion than [Mn(HL1)Cl2(CH3OH)] (1). 相似文献
992.
Six new coordination complexes, Ln2(2,2′-oba)2(phen)2(ox)(H2O)2 (Ln = Eu 1, Tb 2), Ln4(2,2′-oba)6(phen)2 (Ln = Eu 3, Tb 4), Eu4(2,2′-oba)6(phen)2(H2O) (5), and K[Eu(2,2′-oba)2(phen)2] (6) [2,2′-H2oba = 2,2′-oxybis(benzoic acid), phen = 1,10-phenanthroline, H2ox = oxalic acid] were synthesized by hydrothermal reactions with the same compound molar ratios but different modulatory reagents (MRs). Complexes 1–5 have different 1-D chain structures and 6 shows a mononuclear structure. These complexes form diverse 3-D supramolecular networks through hydrogen bonds. The interaction between these complexes and hippuric acid (HA) or bovine serum albumin (BSA) was investigated by fluorescence spectral analysis. Interestingly, the hippuric acid could quench the luminescence of these complexes while the fluorescence of BSA could be quenched by these complexes. Results suggested that the complexes may be potential luminescent testing reagents for HA or BSA by significant fluorescence quenching of Ln3+ or BSA, respectively, through a static and dynamic quenching process. 相似文献
993.
Nurettin Sahiner Sultan Butun Sengel Mustafa Yildiz 《Journal of Coordination Chemistry》2017,70(21):3619-3632
Tannic acid (TA) complexes with various metal ions are prepared in buffer solutions by readily adjusting the pH, but there is no normalizing method to produce ferric tannate complexes. In this study, TA-Fe(III) complex was prepared in reverse microemulsion medium by reaction of TA as ligand with Fe(III) in 1:3 ligand:metal ion molar ratio. The complex was characterized by SEM, AFM, FT-IR, elemental analysis, AAS measurement, and Brunauer-Emmett-Teller (BET) method. Furthermore, magnetic susceptibility was tested with the Gouy method, and electronic spectral studies of TA-Fe(III) complex were completed with solid UV–vis measurements. The thermal stability was also studied by TGA analysis. These studies show that the ligand molecules have octahedral arrangement around Fe(III) and the complex is paramagnetic. The bandgap energy of the complex was calculated as 3.42 eV with solid UV–vis analysis. To determine antioxidant activity of the complex, Total Phenol Content (TPC) and Trolox Equivalent Antioxidant Concentration (TEAC) methods were used. The complex has great antioxidant properties with TPC = 45 ± 1 mg L?1 GAE and TEAC = 296 ± 2 mM trolox g?1 for dry sample. 相似文献
994.
Selçuk Demir Hamide Merve Çepni Małgorzata Hołyńska Muammer Kavanoz Fatih Yilmaz Yunus Zorlu 《Journal of Coordination Chemistry》2017,70(19):3422-3433
Via an oxidation reaction of Cu(I) iodide with pyridine-2,6-dicarboxylic acid (H2L) in DMF three copper(II) complexes, [(CH3)2NH2]2[CuL2] (1), K2[CuL2]?H2L?H2O (2) and [Cu(L)(H2O)]n (3), were synthesized and characterized. The structures of 1–3 were determined by single crystal X-ray diffraction studies. In-situ DMF decomposition produces dimethylamine base under solvothermal conditions and a proton transfer reaction takes place for the complex formation of 1. 3-D networks are stabilized in 1 and 2 via hydrogen bonds. Complex 3 is a 1-D coordination polymer with Cu-O semi-coordination bonds. Thermal decomposition of the complexes results in the corresponding metal oxides. Also, the electrochemical behavior of 1 was determined to be a metal-centered and diffusion-controlled, one-electron reduction process. 相似文献
995.
Linkui Bai Linxiang Cai Qinghua Liu Yunxu Qian Bo Yang 《Journal of Coordination Chemistry》2017,70(22):3759-3768
A series of novel dinuclear platinum(II) complexes with a chiral tetradentate ligand, (1R,1′R,2R,2′R)-N1,N1′-(1,2-phenylenebis(methylene))dicyclohexane-1,2-diamine (HL), and mono-carboxylic acid derivatives as ligands have been designed, synthesized, and characterized. In vitro cytotoxicity evaluation of synthesized complexes against human HepG-2, A549, HCT-116, and MCF-7 cancer cell lines has been conducted by MTT assays. All compounds showed antitumor activity to HepG-2 and HCT-116 cell lines. Compound L2 exhibited better cytotoxicity than that of carboplatin against HepG-2 and A549 cell lines and also showed comparable activity against HCT-116 cell line. 相似文献
996.
Two rare earth carboxylic acid complexes, [Sm(MeBA)3(2,2′-bipy)]2·2(2,2′-bipy) (MeBA = 3-methylbenzoic acid; 2,2′-bipy = 2,2′-bipyridine) (1) and [Pr(MeBA)3(H2O)2]n?n(4,4′-bipy) (4,4′-bipy = 4,4′-bipyridine) (2), have been synthesized under hydrothermal conditions and structurally determined by single-crystal X-ray diffraction. Compound 1 is a dimer and further assembles into an infinite chain, two-dimensional net and three-dimensional supramolecular structure via weak π–π and C–H···π interactions. Some 2,2′-bipy coordinates with Sm and some exist by non-covalent C–H···π interactions. Compound 2 is a 1D infinite chain structure, with adjacent 1D chains connected into a 2D layer structure by O–H···N hydrogen bonds. The two complexes were characterized by elemental analyses, IR, photoluminescence, and TGA. In order to illustrate subtle structural characteristics of intermolecular interactions and magnetic sensitivity of the complex, 2D-IR correlation spectra (2D-IR COS) under magnetic perturbation for 1 were performed. 相似文献
997.
Effect of atomic oxygen irradiation on the structural and tribological characteristics of polytetrafluoroethylene and its composites 下载免费PDF全文
Xiangli Wang Baixing Liu Guoheng Zhang Liwei Liu Qiong Chen Wanjun Chen Xiaoyong Li 《Surface and interface analysis : SIA》2017,49(2):112-116
Based on the ground‐based simulation facility, the effects of atomic oxygen (AO) irradiation on the structural and tribological properties of pure polytetrafluoroethylene (PTFE) and carbon fiber and MoS2‐filled PTFE composites were studied by scanning electron microscopy, X‐ray photoelectron spectroscopy, and a ball‐on‐disc tribometer. The results shown that AO irradiation had significant effects on the structural and tribological properties of pure PTFE, in which the surface morphologies, mass loss, friction coefficient, and wear rate had been changed greatly after AO irradiation. However, it was noticeable that the addition of carbon fiber and MoS2 filler to PTFE could improve the AO resist capacity and tribological properties of PTFE composites significantly. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
998.
Structural,compositional and hardness properties of hydrogenated amorphous carbon nitride thin films synthesized by dense plasma focus device 下载免费PDF全文
Z. A. Umar R. S. Rawat R. Ahmad Z. Chen Z. Zhang J. Siddiqui A. Hussnain T. Hussain M. A. Baig 《Surface and interface analysis : SIA》2017,49(6):548-553
The hydrogenated amorphous carbon nitride (a‐CNx:H) thin films were synthesized on the SS‐304 substrates using a dense plasma focus device. The a‐CNx:H thin films were synthesized using CH4/N2 admixture gas and 20 focus deposition shots on substrates placed at different distances from the anode top. X‐ray photoelectron spectroscopy and Raman analysis confirmed different C–N bonding in the a‐CNx:H thin films. A decrease in the N/C ratio as well as the sp3/sp2 ratio with an increase in the substrate distance has been observed. The higher amount of C–N formation for the film synthesized at 10 cm is observed which decreases with increasing distance. The X‐ray photoelectron spectroscopy and Raman analysis affirmed the C ≡ N presence in all the thin films synthesized at different distances. The morphology of the synthesized a‐CNx:H thin films showed nanoparticles and nanoparticle clusters formation at the surface. The hardness results showed comparatively lower hardness of the a‐CNx:H thin films due to the presence of C ≡ N. The C–N formation with lower amount of C ≡ N and a higher N/C ratio as well as a higher sp3/sp2 ratio for the films synthesized at 10 cm show reasonably higher hardness. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
999.
Improvement of interfacial adhesion in PP/PS blends enhanced with supersonic atmosphere plasma spraying surface‐treated carbon fiber 下载免费PDF全文
The effects of surface treatment of a carbon fiber (CF) by supersonic atmosphere plasma spraying (SAPS) on the interfacial adhesion behavior and morphology of polypropylene/polystyrene (PP/PS) matrix blends filled CF composites were investigated. Effects of surface treated a commercial CF on mechanical properties are studied. Contact angle was measured to examine the changes in wettability of the CF. The chemical and morphological changes were characterized by using X‐ray photoelectron spectroscopy and scanning electron microscopy. PP/PS/CF composites were fabricated with and without SAPS treatment, and their interlaminar fracture toughnesses were compared. The results showed that the interlaminar shear strength of composites has been greatly improved filled SAPS modification CF. The water contact angle of resin sample decreased 50% after addition of SAPS surface‐treated CF. Scanning electron microscopy results on the fractured surface exhibited PP/PS blends adhered well around the CFs of the SAPS‐treated specimen compared with that of the untreated specimen. This attributed to the CF interlock, and it improves the wetting between fibers and resins. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
1000.
Determination of surface ζ‐potential and isoelectric point of carbon surfaces using tracer particle suspensions 下载免费PDF全文
Joana M. Vasconcelos Federico Zen James A. Behan Paula E. Colavita 《Surface and interface analysis : SIA》2017,49(8):781-787
Carbon materials are widely used in a range of applications from biomaterials to sensing and electronics. Many of these applications rely on the ability to control carbon/water interfacial properties, in particular, surface charge density. This work reports a study of the electrokinetic properties of amorphous carbon thin films as a function of pH and surface chemistry. Surface ζ‐potential (SZP) and isoelectric point were determined using the tracer particle method. Initially, the use of sulfonated and amine‐terminated latex bead suspensions as tracer particles for the determination of SZP of reference polymer surfaces was validated. The tracer particle method was then applied to the determination of SZP and isoelectric point of macroscopic carbon surfaces with different surface chemistry. Highly graphitic and sp3‐rich hydrogenated carbon surfaces were found to display negative SZP, as expected for hydrophobic surfaces. The isoelectric point of the most highly graphitic surface was found to be pHiso = 3.7. Surface oxidation of these films resulted in a decrease of SZP at all pH values and in a downshift of pHiso to values lower than 1.5, consistently with the presence of surface acidic groups arising from oxidation. Results indicate that the specific choice of acid/base chemistry for the tracer particles does not significantly affect either SZP or pHiso determinations. These results show that the tracer particle method in combination with widely available latex beads as tracers can be applied for the determination of carbon SZP as a function of pH. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献