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Chen Luo Chenggang Zhou Jinping Wu T. J. Dhilip Kumar Naduvalath Balakrishnan Robert C. Forrey Hansong Cheng 《International journal of quantum chemistry》2007,107(7):1632-1641
Structures and physical properties of small palladium clusters Pdn up to n = 15 and several selected larger clusters were studied using density functional theory under the generalized gradient approximation. It was found that small Pdn clusters begin to grow 3‐dimensionally at n = 4 and evolve into symmetric geometric configurations, such as icosahedral and fcc‐like, near n = 15. Several isomers with nearly degenerate average binding energies were found to coexist and the physical properties of these clusters were calculated. For several selected isomers, relatively moderate energy barriers for structural interchange for a given cluster size were found, implying that isomerization could readily occur under ambient conditions. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007 相似文献
124.
S. P. Tunik S. I. Pomogailo G. I. Dzhardimalieva A. D. Pomogailo I. I. Chuev S. M. Aldoshin A. B. Nikol'skii 《Russian Chemical Bulletin》1993,42(5):937-942
Mono- and disubstituted cluster metal-containing monomers were obtained under mild conditions on interaction of Rh6(CO)16 with 4-vinylpyridine (4-ViPy) in the presence of N-trimethylaminoxide. These products were characterized by IR and1H NMR spectroscopy and by elemental and X-ray analyses. Rh6(CO)15(4-ViPy) was found to be an octahedral cluster with eleven terminal and four 3-bridging carbonyl ligands. 4-ViPy is linked with the Rh(3) atom through the N atom and occupies the coordination site of the twelfth CO terminal ligand. The mean value of the Rh-Rh bond length is 2.762 Å. The unsaturated ligand has little or no effect on the geometry of the starting cluster and its double bond retains the ability to undergo addition reactions.For part 28, seeRuss. Chem. Bull., 1993, 453.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 975–979, May, 1993. 相似文献
125.
含羧酸配体的鼓形有机锡氧簇合物:六聚苯基锡氧3-吲哚丁酸酯的合成及晶体结构 总被引:7,自引:0,他引:7
利用Ph3SnOH和3-吲哚丁酸以1:1摩尔比反应,合成了新型含羧酸配体的鼓形 有机锡氧簇合物:六聚苯基锡氧3-吲哚西酸酯。通过元素分析、红外光谱和X射线 单晶衍射对其结构进行了表征。测试结果表明:该化合物为三斜晶系,空间群P1, a=1.1722(6),b=1.5694(8)nm,c=1.7227(9)nm,α=116.251(8)°,β=100. 854(10)°,γ=95.606(9)°,Z=1,V=2.732(3)nm^3,Dc=1.554g·cm^-3,μ =1.420mm^-1,F(000)=1276,R=0.0630,ωR=0.0762。晶体结构中,六配位的锡原 子呈畸变的八面体构型。 相似文献
126.
127.
(μ3-S)FeCo2(CO)7(dppfe)的合成和晶体结构 总被引:1,自引:0,他引:1
通过简单取代反应,合成了一个新的混金属簇合物(μ3-S)FeCo2(CO)7(dppfe) (2) (dppfe=Ph2PC5H4FeC5H4PPh2).利用IR,1H NMR,MS 和 X-ray单晶衍射的方法对簇合物2进行了结构表征.簇合物2的晶体属于三斜晶系,空间群为Pī.晶胞参数: a=1.132 4(15) nm, b=1.3670(17) nm, c=1.5769(2) nm,α=114.646(2)°,β=100.340(2)°,γ=100.113(3)°, V=2.0953(5) nm3. 相似文献
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129.
Royston C. B. Copley Christopher M. Hill D. Michael P. Mingos 《Journal of Cluster Science》1995,6(1):71-91
[Au2Pd14(3-CO)7(2-CO)2(PMe3)11](PF6)2 has been synthesized from [Pd8(CO)8(PMe3)7] and AuCl(PCy3) in the presence of TIPF6. It has been characterised on the basis of mass spectrometry, infrared and NMR spectroscopy, and a single crystal X-ray diffraction study. The structure is based on a palladium-centered Au2Pd11 icosahedron which shares an edge with a Pd5 trigonal bipyramid.This paper is dedicated to Larry Dahl on his 65th Birthday—his enthusiasm and achievements in cluster chemistry have inspired us all for more than 30 years. 相似文献
130.
O. Penrose 《Journal of statistical physics》1995,78(1-2):267-283
The grand potentialP(z)/kT of the cluster model at fugacityz, neglecting interactions between clusters, is defined by a power series
n
Q
n
z
n
, whereQ
n
, which depends on the temperatureT, is the partition function of a cluster of sizen. At low temperatures this series has a finite radius of convergencez
s
. Some theorems are proved showing that ifQ
n
, considered as a function ofn, is the Laplace transform of a function with suitable properties, thenP(z) can be analytically continued into the complexz plane cut along the real axis fromz
s
to + and that (a) the imaginary part ofP(z) on the cut is (apart from a relatively unimportant prefactor) equal to the rate of nucleation of the corresponding metastable state, as given by Becker-Döring theory, and (b) the real part ofP(z) on the cut is approximately equal to the metastable grand potential as calculated by truncating the divergent power series at its smallest term. 相似文献