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91.
Yasuhiro Morisaki 《Journal of organometallic chemistry》2004,689(16):2684-2689
Novel organometallic conjugated polymer containing (η6-arene)Cr(CO)3 and platinum in the main chain was synthesized by dehydrohalogenation coupling reaction of (η6-1,4-diethynylbenzene)tricarbonylchromium with trans-(PBu3)2PtCl2. The polymer was soluble in common organic solvents and has the number-average molecular weight of 31,000 by GPC analysis. The polymer exhibited an absorption peak derived from π-π∗ interaction at 358 nm in the UV-Vis spectrum, which showed a red shift of approximately 90 nm compared to that of the model compound. The photochemical ligand exchange reaction of the polymer was also investigated. 相似文献
92.
Michael Knorr Isabelle Jourdain Carsten Strohmann 《Journal of organometallic chemistry》2005,690(6):1456-1466
Insertion of hexafluorobutyne into the Pt-H bond of the heterobimetallic complexes [(OC)3Fe{Si(OMe)3}(μ-Ph2PXPPh2)Pt(H)(PPh3)] (1a X = CH2; 1b X = NH) yields the σ-alkenyl complexes [(OC)3Fe{μ-Si(OMe)2(OMe)}(μ-Ph2PXPPh2)Pt{C(CF3)C(H)CF3}] (3a X = CH2; 3b X = NH). This insertion reaction is accompanied by dissociation of the platinum bound PPh3 ligand and saturation of the vacant coordination site by a dative μ−η2-Si-O → Pt interaction. Addition of the Pt-H bond of 1a across the triple bond of 3,3,3-trifluoropropyne affords in a regiospecific manner [(OC)3Fe{μ-Si(OMe)2(OMe)}(μ-dppm)Pt{C(CF3)CH2}] (2) having the trifluoromethyl substituent on the α-carbon. Addition of RNC to 3 affords the isocyanide adducts [(OC)3Fe{Si(OMe)3}(μ-Ph2PXPPh2)Pt(CNR){C(CF3)C(H)CF3}] (4a R = t-Bu, X = CH2; 4b R = 2,6-xylyl, X = CH2; 4c R = 2,6-xylyl, X = NH). In dichloromethane solution 3a is gradually transformed into the C4F6-bridged compound [(OC)3Fe(μ-dppm)(μ-CF3CCCF3)Pt(CO)] 5. The Pt-bound carbonyl ligand of 5 is displaced by xylylisocyanide or trimethylphosphite affording the derivatives [(OC)3Fe(μ-dppm)(μ-CF3CCCF3)Pt(CNxylyl)] 6 and [(OC)3Fe(μ-dppm)(μ-CF3CCCF3)Pt{P(OMe)3}] 7. The molecular structures of 4a, 5 and 6 have been determined by X-ray diffraction studies. 相似文献
93.
Nickel foam and five nickel foam-based composite electrodes were prepared for being used as anode materials for the electrooxidation
of methanol in KOH solution containing 0.1 and 1.0 M of methanol. The layered electrodes composed of nickel foam, platinum
nanoparticles, polyaniline (PANI) and/or porous carbon (C) prepared in various assemblies. As shown by SEM analysis, depending
on the preparation conditions, the electrodes of different morphologies were obtained. Using the cyclic voltammetry method,
the oxidation of methanol on nickel foam electrode was observed in the potential range 0.4 V ↔ 0.7 V, where the Ni(OH)2/NiOOH transformation occurred. The presence of Pt particles in electrode gave rise to the increase in electrocatalytic activity
in this potential range. For electrodes containing dispersed platinum catalyst (Ni/Pt, Ni/PANI/Pt and Ni/C/Pt), the oxidation
of methanol was noted also in the potential range −0.5 V ↔ 0.1 V. The electrocatalytic activities of the examined electrodes
toward methanol oxidation at low potentials were in order Ni/Pt > Ni/C/Pt > Ni/PANI/Pt, whereas at high potentials in order
Ni/PANI/Pt > Ni/Pt> Ni/C/Pt > Ni. Among the examined electrodes, the most resistant to cyclic poisoning appeared to be the
Ni/C/Pt electrode.
Presented at the 4Th Baltic Conference on Electrochemistry, Greifswald, March 13–16, 2005 相似文献
94.
采用透射电镜(TEM)和选区电子衍射(SAED)技术, 分别表征了Pt-CNTs/GC电极的表面形貌和所负载铂纳米原子簇的结构. 以CO和CH3OH为探针分子, 用循环伏安和计时电流等常规电化学方法检测了CO和CH3OH在Pt-CNTs/GC电极上的氧化行为. 研究结果表明, CO在Pt-CNTs/GC电极上有3个氧化电流峰(Ⅰ, Ⅱ, Ⅲ), 其中峰Ⅰ为CO桥式吸附的氧化峰, 而峰Ⅱ和Ⅲ则分别为CO线形吸附在碳纳米管负载的不同粒径的Pt纳米原子簇以及Pt原子薄膜上所分裂的氧化峰; CH3OH在Pt-CNTs/GC电极上也能自发解离吸附强吸附中间体CO; Pt-CNTs/GC电极对CH3OH的氧化峰电流不总是随CNTs上载铂量的增加而增大, 表明在制备直接甲醇燃料电池阳极时, 应选择合适的载铂量. 相似文献
95.
Jeroen W. Sprengers Marcel A. Duin Cornelis J. Elsevier 《Journal of organometallic chemistry》2003,679(2):149-152
A highly active and selective in situ formed platinum(N-heterocyclic carbene) catalyst for the hydrosilylation of styrene with triethylsilane is described, which unlike all other known hydrosilylation catalysts, selectively yields hydrosilylation products, but (almost) no dehydrogenative silylation products. 相似文献
96.
Reaction of 3-methoxycarbonyl-2-methyl- or 3-dimethoxyphosphoryl-2-methyl-substituted 4-oxo-4H-chromones 1 with N-methylhydrazine resulted in the formation of isomeric, highly substituted pyrazoles 4 (major products) and 5 (minor products). Intramolecular transesterification of 4 and 5 under basic conditions led, respectively, to tricyclic derivatives 7 and 8. The structures of pyrazoles 4a (dimethyl 2-methyl-4-oxo-4H-chromen-3-yl-phosphonate) and 4b (methyl 4-oxo-2-methyl-4H-chromene-3-carboxylate) were confirmed by X-ray crystallography. Pyrazoles 4a and 4b were used as ligands (L) in the formation of ML2Cl2 complexes with platinum(II) or palladium(II) metal ions (M). Potassium tetrachloroplatinate(II), used as the metal ion reagent, gave both trans-[Pt(4a)2Cl2] and cis-[Pt(4a)2Cl2], complexes with ligand 4a, and only cis-[Pt(4b)2Cl2] isomer with ligand 4b. Palladium complexes were obtained by the reaction of bis(benzonitrile)dichloropalladium(II) with the test ligands. trans-[Pd(4a)2Cl2] and trans-[Pd(4b)2Cl2] were the exclusive products of these reactions. The structures of all the complexes were confirmed by IR, 1H NMR and FAB MS spectral analysis, elemental analysis and Kurnakov tests. 相似文献
97.
Marketa Ryvolova Kristyna Smerkova Jana Chomoucka Jaromir Hubalek Vojtech Adam Rene Kizek 《Electrophoresis》2013,34(6):801-808
Cisplatin, carboplatin, and oxaliplatin represent three generations of platinum based drugs applied successfully for cancer treatment. As a consequence of the employment of platinum based cytostatics in the cancer treatment, it became necessary to study the mechanism of their action. Current accepted opinion is the formation of Pt‐DNA adducts, but the mechanism of their formation is still unclear. Nanomaterials, as a progressively developing branch, can offer a tool for studying the interactions of these drugs with DNA. In this study, fluorescent CdTe quantum dots (QDs, λem = 525 nm) were employed to investigate the interactions of platinum cytostatics (cisplatin, carboplatin, and oxaliplatin) with DNA fragment (500 bp, c = 25 μg/mL). Primarily, the fluorescent behavior of QDs in the presence of platinum cytostatics was monitored and major differences in the interaction of QDs with tested drugs were observed. It was found that the presence of carboplatin (c = 0.25 mg/mL) had no significant influence on QDs fluorescence; however cisplatin and oxaliplatin quenched the fluorescence significantly (average decrease of 20%) at the same concentration. Subsequently, the amount of platinum incorporated in DNA was determined by QDs fluorescence quenching. Best results were reached using oxaliplatin (9.4% quenching). Linear trend (R2 = 0.9811) was observed for DNA platinated by three different concentrations of oxaliplatin (0.250, 0.125, and 0.063 mg/mL). Correlation with differential pulse voltammetric measurements provided linear trend (R2 = 0.9511). As a conclusion, especially in the case of oxaliplatin‐DNA adducts, the quenching was the most significant compared to cisplatin and nonquenching carboplatin. 相似文献
98.
Lei Sun Jiahui Geng Dr. Mengyou Gao Dr. Dehua Zheng Zhongxin Jing Qingyun Zhao Prof. Jianjian Lin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(42):10998-11004
Fe0.95S1.05 with high reactivity and stability was incorporated into WS2 nanosheets via a one-step solvothermal method for the first time. The resulted hybrid catalyst has much higher catalytic activity than WS2 and Fe0.95S1.05 alone, and the optimal WS2/Fe0.95S1.05 hybrid catalyst was found by adjusting the feed ratio. The addition of Fe0.95S1.05 was proven to be able to enhance the hydrogen evolution reaction (HER) activity of WS2, and vice versa. At the same time, it was found that the catalytic effect of the hybrid catalyst was the best when the feed ratio was W : Fe=2 : 1. In other words, we confirmed that there is a synergistic effect between W- and Fe-based sulfide hybrid catalysts, and validated that the reason for the improved HER performance is the strong interaction between the two in the middle sulfur. WS2/Fe0.95S1.05-2 hybrid catalyst leads to enhanced HER activity, which shows a low overpotential of ∼0.172 V at 10 mA cm−2, low Tafel slope of ∼53.47 mV/decade. This study supplies innovative synthesis of a highly active WS2/Fe0.95S1.05 hybrid catalyst for HER. 相似文献
99.
《Journal of Coordination Chemistry》2012,65(9):795-801
Platinum(II) forms blue 1?:?2 coordination compounds with 1-phenylthiosemicarbazide [H(1-PTSC)], 4-phenylthiosemicarbazide [H(4-PTSC)], 1,4-diphenylthiosemicarbazide [H(1,4-DPTSC)] and 4-(2-pyridyl)-thiosemicarbazide [H(4-(2py)-TSC)]. Electronic spectra of these compounds have been studied in different solvents. In all compounds, a band is observed in the 650–750?nm region that appears to be a metal-to-ligand charge transfer band. Infrared and proton NMR studies have been carried out to determine possible coordination sites and the nature of the complexes. IR spectra indicate bonding through sulfur and nitrogen and proton NMR spectra indicate bonding through the N1nitrogen. 相似文献
100.
《Electroanalysis》2017,29(3):898-906
Platinum nanoparticles (NPs) modified with undecafluorohexylamine (UFHA) and octylamine were synthesized as a novel model cathode catalyst for fuel cells. The modified Pt NPs were well characterized by FTIR, X‐ray photoelectron spectroscopy, thermogravimetric analysis, and transmission electron microscopy. These NPs supported on carbon black were applied as electrocatalysts for the oxygen reduction reaction. The UFHA‐modified Pt NP catalyst showed high electrocatalytic activity and durability compared to a commercial catalyst. Besides suppression of undesired oxide formation on the Pt surface, the affinity between the perfluorinated alkyl chains of UFHA and Nafion® improved the catalyst activity by creating a desirable proton conduction path. Additionally, UFHA modification improved durability by suppressing Pt dissolution and carbon corrosion because of restricted water accessibility. The β ‐oxide formation, which is responsible for Pt dissolution, was significantly attenuated by surface modification. 相似文献