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81.
《Journal of Coordination Chemistry》2012,65(15):1693-1701
Six diorganotin esters of Schiff-base ligands formulated as [R2SnLY]2, where L1 is C6H5CON2C(CH3)CO2 with Y?=?CH3CH2OH, R?=?mClC6H4CH2 (1), oFC6H4CH2 (2), pFC6H4CH2 (3) and L2 is 2-HOC6H4CON2C(CH3)CO2 with Y?=?CH3OH, R?=?oFC6H4CH2 (4), pFC6H4CH2 (5), mClC6H4CH2 (6) have been prepared and characterized by elemental analysis, IR, 1H and 119Sn NMR spectra. The crystal structures of complexes 1 and 4 have been determined by X-ray single crystal diffraction. The structure analyses reveal that the Sn atom in both 1 and 4 is seven-coordinate in distorted pentagonal bipyramid geometries with a planar SnO4N unit and two apical aryl carbon atoms, thus forming a dimeric molecule, which sits on a crystallographic center of symmetry. Intramolecular or intradimeric hydrogen bonds contribute to the stability and compactness of the crystal structures. 相似文献
82.
《Journal of Coordination Chemistry》2012,65(19):3395-3402
The reaction of 2-thiazoline-2-thione (TZDSH) with SnR2Cl2 (R=Ph 1, Me 2, Bu 3) in dry ethanol in the presence of sodium ethoxide leads to [SnR2(C3H4NS2)2] (1, 2, and 3), respectively. Reaction between TZDSH and SnPh2Cl2 in dichloromethane and dry ethanol in an inert atmosphere produces [SnPh2Cl2(C3H5NS2)2] (4). The yields of the products were over 80%. These new complexes have been characterized by IR, UV-Vis, multinuclear (1H, 13C, and 119Sn) NMR spectroscopy, and mass spectrometry, as well as elemental analysis. 相似文献
83.
A density-functional theory investigation on desorption of O2 on Sn(111) and its comparison with initial oxidation on the X(111) (X=Si,Ge, Sn,Pb) surfaces
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<正>The first-principles calculations are performed to investigate the adsorption of O2 molecules on an Sn(111) 2×2 surface.The chemisorbed adsorption precursor states for O2 are identified to be along the parallel and vertical channels, and the surface reconstructions of Sn(lll) induced by oxygen adsorption are studied.Based on this,the adsorption behaviours of O2 on X(111)(X=Si,Ge,Sn,Pb) surfaces are analysed,and the most stable adsorption channels of O2 on X(111)(X=Si,Ge,Sn,Pb) are identified.The surface reconstructions and electron distributions along the most stable adsorption channels are discussed and compared.The results show that the O2 adsorption ability declines gradually and the amount of charge transferred decreases with the enhancement of metallicity. 相似文献
84.
The hyperfine interaction of 111Cd in ferromagnetic Fe3Sn compound was investigated by TDPAC in the paramagnetic region and below the Curie temperature. The results are compared
with hyperfine magnetic fields and EFGs on 111Cd and 119Sn in other stoichiometric Fe–Sn phases.
This revised version was published online in September 2006 with corrections to the Cover Date. 相似文献
85.
碘化物升华分离-电感耦合等离子体光谱法测定土壤和沉积物中砷、锑、铋、镉、锡 总被引:3,自引:0,他引:3
将土壤或水系沉积物样品与固体NH4I按1:0·25的比例在双球玻璃管中混匀后在苯灯喷焰上加热,使样品中的As,Sb,Bi,Cd和Sn转变为碘化物升华逸出而与基体分离,挥发物用盐酸溶解后用电感耦合等离子体光谱法(ICP-AES)测定。实验探讨了NH4I的用量、挥发和溶解条件,光谱测定条件,内标选择,测定谱线选择及背景和谱线干扰校正。用土壤和水系沉积物国家一级标准物质验证了方法的准确性和精密度,测定结果与标准值吻合。方法快速简便,结果可靠,检出限为0·01~0·35μg·g-1,适用于地球化学勘探大批量土壤和沉积物样品中As,Sb,Bi,Cd和Sn的测定。 相似文献
86.
超导技术是21世纪具有重大经济和战略意义的高新技术,在国民经济诸多领域具有广阔的应用前景,如在超导弱电应用中的超导量子干涉器、滤波器;在超导强电应用中的电缆、限流器、电机、储能系统、变压器、磁体技术、医疗核磁共振成像、高能物理实验和高速交通输运等。实用化超导材料是超导技术发展的基础。目前,国际上发现的实用化超导材料主要有低温超导线材、铋系高温超导带材、YBCO涂层导体、MgB2线带材以及新型铁基超导线带材。文章在简要介绍超导材料发展历程的基础上,重点综述了上述实用化超导材料制备及加工、性能和应用方面的最新研究进展,并对相关领域存在的问题及今后的发展作出展望。 相似文献
87.
Jaclyn Catalano Valeria Di Tullio Molly Wagner Nicholas Zumbulyadis Silvia A. Centeno Cecil Dybowski 《Magnetic resonance in chemistry : MRC》2020,58(9):798-811
Heavy metal carboxylate or soap formation is a widespread deterioration problem affecting oil paintings and other works of art bearing oil-based media. Lead soaps are prevalent in traditional oil paintings because lead white was the white pigment most frequently chosen by old masters for the paints and in some cases for the ground preparations, until the development of other white pigments from approximately the middle of the 18th century on, and because of the wide use of lead-tin yellow. In the latter part of the 19th century, lead white began to be replaced by zinc white. The factors that influence soap formation have been the focus of intense study starting in the late 1990s. Since 2014, nuclear magnetic resonance (NMR) studies have contributed a unique perspective on the issue by providing chemical, structural, and dynamic information about the species involved in the process, as well as the effects of environmental conditions such as relative humidity and temperature on the kinetics of the reaction(s). In this review, we explore recent insights into soap formation gained through solid-state NMR and single-sided NMR techniques. 相似文献
88.
Hong-Lei Xu Chad Studvick Dr. Chao Liu Dr. Yuan Xue Prof. Dr. Ivan A. Popov Prof. Dr. Zhong-Ming Sun 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(64):e202202651
Group 14 endohedral clusters containing a metal center inside usually possess a single cage topological structure, but here an unexpected single-metal-filled double-cage cluster, [Pt@Sn17]4− ( 1 a ) is reported. It can be seen as a combination of the more extended Pt-filled [Pt@Sn9] cage and hollow [Sn9] cage sharing a central Sn atom, which is offset from the central position. This double-cage species represents the largest group 14 intermetalloid cluster encapsulating a single transition metal atom. DFT calculations show that the capsule-like architecture of [Sn17]4−, similar to that found in [Pt2@Sn17]4−, is unstable if filled with a single Pt atom and collapses to the title cluster 1 a upon geometry optimization. Deviation of the central Sn atom occurs due to the vibronic coupling as a consequence of pseudo-Jahn-Teller distortion leading to the bent Cs-symmetrical structure, in contrast to the more symmetrical D2d cage previously reported in [Ni2@Sn17]4−. 相似文献
89.
CO2 electrocatalysis as a hydrocarbon is a promising means of achieving economical CO2-mediated hydrogen energy cycling. Hydrocarbons are renewable hydrogen storage materials. The development of reliable metal alloy electrocatalysts is an urgent but challenging task associated with such systems, although there is still a lack of precise reaction mechanism design. In this study, the performance of Pd10Ag5 alloy nanoparticles (NPs) and Pd10Sn5 alloy nanoparticles (NPs) on the electrocatalytic reaction of CO2 was compare. The kinetic and density functional theory (DFT) calculations show that the selectivity of the Pd-based bimetallic catalyst to the C2 product is greater than that of C1, and the stability of Pd10Ag5 is better and less affected by the reaction environment. However, the catalytic performance of the Pd10Sn5 electrocatalyst in the liquid phase is the best. The insight obtained from the calculations is used to develop criteria for identifying new and improved catalysts for electrochemical CO2 reduction. 相似文献
90.
Katsuhiko Tahara Eiji Nagahara Yasushi Itoi Satoru Nishiyama Shigeru Tsuruya Mitsuo Masai 《Reaction Kinetics and Catalysis Letters》1996,59(1):15-18
The conversion of a carboxylic acid was increased to 90% with 100% selectivity to the corresponding alcohol by calcination of the catalyst precursor, Sn/alumina, of Ru–Sn/alumina in the hydrogenation of the carboxylic acid. 相似文献