THEORETICAL-STUDIES ON THE STABILITY OF M8C12 CLUSTERS

被引：79

作者：

LIN, ZY ^{[1
]}

HALL, MB ^{[1
]}

机构：

[1] TEXAS A&M UNIV SYST,DEPT CHEM,COLL STN,TX 77843

来源：

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY | 1993年 / 115卷 / 24期

关键词：

D O I：

10.1021/ja00077a014

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Ab initio calculations with effective core potentials were completed on M8C12 (M = Y, Zr, Nb, and Mo) clusters. Three different isomers (T(h), D3d, and T(d)) have been investigated. The T(h) and D3d isomers are derived from a dodecahedral geometry. In the former, the faces of a cube of the metal atoms are capped by ethylene-like C2 units, while in the latter the 12 carbons form a cylindrical, closed chain capped by two M4 units. In the T(d) isomer, six acetylene-like C2 units link the vertices of a tetracapped tetrahedral metal framework in a butterfly fashion. Our calculations show that the observed M8C12 (M = Ti, Zr, Hf, V, Mo or W) clusters most likely adopt a structure similar to the T(d) structure rather than one of the dodecahedral structures. The T(d) structure is more stable than the T(h) or D3d structure by more than 200 kcal/mol. Molecular orbital analyses of the bonding in the T(d) structure allow us to derive ''magic numbers' of metal electrons, i.e., 18 and 36 when we formulate the cluster as (M8)12+(C2(2-))6. The unique geometry and electronic structure are responsible for the observation of high stability of these metal-carbon clusters. In the group 4 clusters, a dicationic cluster, e.g., [Ti8C12]2+, may be the best target to be isolated in the solid state as an ion.

引用

页码：11165 / 11168

页数：4

共 30 条

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