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991.
992.
长链线性配合物具有特有的结构、成键和性质,在分子器件和特殊性能低维材料等方面展示出潜在的应用前景。在低价状态下,铂系金属可自聚合形成一类含有多个金属原子的线性金属链式簇合物。本文就有关线性低价铂系金属簇合物的研究进展作一简述。 相似文献
993.
JI Zhi Abraham F. Jalbou LI Jun-Qian 《结构化学》2007,26(7):843-849
Density functional theory periodic slab calculations were carried out for CO adsorption on a series of Mo modified Pt(111) surfaces to provide an insight into the interaction between CO and doped metal surface, an important issue in CO oxidation as well as in promotion and poisoning effects of catalysis. The modification of adsorption properties with respect to those of adsorption on the pure Mo(110) and Pt(111) is described in terms of changes in the adsorption energies, adsorption sites and vibrational properties occurring upon alloying. We believe that the present DFT calculations can provide important information into optimal alloy composition for CO-tolerance, which is not easily obtained by experimental methods. 相似文献
994.
磁动式测氧仪中铂丝哑铃球系统的研究 总被引:5,自引:0,他引:5
磁动式测氧仪是一种良好的测量气体含氧量的设备。从氧气是顺磁性、氮气为抗磁性物质,且氧气的磁化率显著高于其它气体的特点出发,分析了磁动式测氧仪测量混合气体中氧气含量的原理,分析了充氮玻璃哑铃球系统在非均匀梯度磁场中的受力情况,报道了磁动式测氧仪的核心部件——铂丝哑铃球反射镜系统的设计方案,并介绍了其技术性能和实现方案。设计一个光学装置,有效地调节了铂丝哑铃球反射镜系统的质心平衡问题。实验结果表明,该系统的稳定性、灵敏度和转动阻尼等性能良好。 相似文献
995.
Evgeny Filatov Pavel Smirnov Dmitry Potemkin Denis Pishchur Natalya Kryuchkova Pavel Plyusnin Sergey Korenev 《Molecules (Basel, Switzerland)》2022,27(4)
The thermal behaviour of Ag2[PtCl4] and Ag2[PtCl6] complex salts in inert and reducing atmospheres has been studied. The thermolysis of compounds in a helium atmosphere is shown to occur in two stages. At the first stage, the complexes decompose in the temperature range of 350–500 °C with the formation of platinum and silver chloride and the release of chlorine gas. At the second stage, silver chloride is sublimated in the temperature range of 700–900 °C, while metallic platinum remains in the solid phase. In contrast to the thermolysis of Ag2[PtCl6], the thermal decomposition of Ag2[PtCl4] at 350 °C is accompanied by significant heat release, which is associated with disproportionation of the initial salt to Ag2[PtCl6], silver chloride, and platinum metal. It is confirmed by DSC measurements, DFT calculations of a suggested reaction, and XRD. The thermolysis of Ag2[PtCl4] and Ag2[PtCl6] compounds is shown to occur in a hydrogen atmosphere in two poorly separable steps. The compounds are decomposed within 170–350 °C, and silver and platinum are reduced to a metallic state, while a metastable single-phase solid solution of Ag0.67Pt0.33 is formed. The catalytic activity of the resulting nanoalloy Ag0.67Pt0.33 is studied in the reaction of CO total (TOX) and preferential (PROX) oxidation. Ag0.67Pt0.33 enhanced Pt nano-powder activity in CO TOX, but was not selective in CO PROX. 相似文献
996.
以非离子表面活性剂四氧乙烯基正十二烷基醚与氯铂酸水溶液构建层状溶致液晶, 通过电沉积技术制备了金属铂纳米线. 分别采用偏光显微镜、小角X射线散射对液晶进行结构分析, 通过透射电镜和能量弥散X射线谱分析观测产物形貌并确定其组成. 结果表明, 相对于饱和甘汞电极, 沉积电势在0.05~0.20 V范围内, 金属铂沿表面活性剂双分子层膜生长, 反应前后液晶相的长程周期性结构无明显变化; 在0.10 V沉积电势下, 随反应时间从960 s延长至3840 s, 去除表面活性剂后沉积产物分别为层状纳米粒子、层状纳米线以及长度达十几微米且致密的纳米线. 讨论了层状液晶对沉积产物的结构导向作用. 相似文献
997.
A Raman micro-focusing accessory has been designed for use with conventional laser Raman spectrometers and offers the advantage of allowing standard macro-Raman experiments to be done without removing the micro-focusing optics. Samples may be analysed with a spatial resolution adjustable to a limit of 1 μm. The viewing magnification can be varied without affecting the size of the laser focal spot. A thermocouple can be attached to the sample holder which may be flushed with cooled N2 gas for increased sample stability. The usefulness of the Raman microprobe for the analysis of solid and fluid inclusions in geological samples is also demonstrated. 相似文献
998.
Cross‐coupling reactions in water using ionic liquid‐based palladium(II)–phosphinite complexes as outstanding catalysts
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Nermin Meriç Murat Aydemir Uğur Işik Yusuf Selim Ocak Khadichakhan Rafikova Salih Paşa Cezmi Kayan Feyyaz Durap Alexey Zazybin Hamdi Temel 《应用有机金属化学》2014,28(11):818-825
Two new phosphinite ligands based on ionic liquids [(Ph2PO)C7H14N2Cl]Cl ( 1 ) and [(Cy2PO)C7H14N2Cl]Cl ( 2 ) were synthesized by reaction of 1‐(3‐chloro‐2‐hydoxypropyl)‐3‐methylimidazolium chloride, [C7H15N2OCl]Cl, with one equivalent of chlorodiphenylphosphine or chlorodicyclohexylphosphine, respectively, in anhydrous CH2Cl2 and under argon atmosphere. The reactions of 1 and 2 with MCl2(cod) (M = Pd, Pt; cod = 1,5‐cyclooctadiene) yield complexes cis‐[M([(Ph2PO)C7H14N2Cl]Cl)2Cl2] and cis‐[M(Cy2PO)C7H14N2Cl]Cl)2Cl2], respectively. All complexes were isolated as analytically pure substances and characterized using multi‐nuclear NMR and infrared spectroscopies and elemental analysis. The catalytic activity of palladium complexes based on ionic liquid phosphinite ligands 1 and 2 was investigated in Suzuki cross‐coupling. They show outstanding catalytic activity in coupling of a series of aryl bromides or aryl iodides with phenylboronic acid under the optimized reaction conditions in water. The complexes provide turnover frequencies of 57 600 and 232 800 h?1 in Suzuki coupling reactions of phenylboronic acid with p‐bromoacetophenone or p‐iodoacetophenone, respectively, which are the highest values ever reported among similar complexes for Suzuki coupling reactions in water as sole solvent in homogeneous catalysis. Furthermore, the palladium complexes were also found to be highly active catalysts in the Heck reaction affording trans‐stilbenes. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
999.
Dr. Rakesh K. Pathak Sean Marrache Joshua H. Choi Trenton B. Berding Prof. Dr. Shanta Dhar 《Angewandte Chemie (International ed. in English)》2014,53(7):1963-1967
Cancer‐associated inflammation induces tumor progression to the metastatic stage, thus indicating that a chemo‐anti‐inflammatory strategy is of interest for the management of aggressive cancers. The platinum(IV) prodrug Platin‐A was designed to release cisplatin and aspirin to ameliorate the nephrotoxicity and ototoxicity caused by cisplatin. Platin‐A exhibited anticancer and anti‐inflammatory properties which are better than a combination of cisplatin and aspirin. These findings highlight the advantages of combining anti‐inflammatory treatment with chemotherapy when both the drugs are delivered in the form of a single prodrug. 相似文献
1000.
Pablo Ríos Dr. Josefina Díez Dr. Joaquín López‐Serrano Dr. Amor Rodríguez Dr. Salvador Conejero 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(47):16791-16795
The low‐electron‐count cationic platinum complex [Pt(ItBu’)(ItBu)][BArF], 1 , interacts with primary and secondary silanes to form the corresponding σ‐SiH complexes. According to DFT calculations, the most stable coordination mode is the uncommon η1‐SiH. The reaction of 1 with Et2SiH2 leads to the X‐ray structurally characterized 14‐electron PtII species [Pt(SiEt2H)(ItBu)2][BArF], 2 , which is stabilized by an agostic interaction. Complexes 1 , 2 , and the hydride [Pt(H)(ItBu)2][BArF], 3 , catalyze the hydrosilation of CO2, leading to the exclusive formation of the corresponding silyl formates at room temperature. 相似文献