Département de chimie, Université Cadi Ayyad, Faculté des Sciences Semlalia, BP 2390, Marrakech 40000, Morocco.
J Mol Model. 2012 Jul;18(7):3321-8. doi: 10.1007/s00894-011-1335-6. Epub 2012 Jan 19.
Do alanes Al(n)H(n+2) and gallanes Ga(n)H(n+2) satisfy the polyhedral skeletal electron pair theory (PSEPT)? Taking into account previous work on this question, this paper provides a convincing answer and proposes the reformulation of the (n + 1) electron pairs rule of Wade and Mingos (W-M) for such systems. Following recent studies of tetra-, penta-, hexa-, hepta-, octa-, and nonaalanes as well as valence-isoelectronic/related gallanes, in this paper we present an analysis of the hydrides of aluminum and gallium A(n)H(n+2) (A = Al, Ga and n = 7-9). The aim is still to examine the applicability of PSEPT, especially the W-M rule, to these clusters. Exploration of the total potential energy surfaces (PESs) of hepta-, octa-, and nonagallanes shows that the absolute minima have a nido-like polyhedron arrangement. Unlike the smaller Ga(n)H(n+2) (n = 4, 5, 6), it seems that the size of the cluster largely dictates its preferred geometry. Although none of them have closed (totally triangular) cages, these clusters exhibit significant compactness, comparable to borane double anions, B(n)H(n) (2-), which are the archetypes for the PSEPT theory.
烷基金属氢化物 Al(n)H(n+2) 和镓基金属氢化物 Ga(n)H(n+2) 是否满足多面体骨架电子对理论 (PSEPT)？考虑到之前对此问题的研究，本文提供了一个令人信服的答案，并提出了 Wade 和 Mingos（W-M）规则对这类系统的（n + 1）电子对规则的重新表述。继最近对四、五、六、七、八和九元烷基金属以及价电子等电子/相关镓基金属的氢化物的研究之后，本文对铝和镓的氢化物 A(n)H(n+2)（A = Al，Ga 和 n = 7-9）进行了分析。目的仍然是检验 PSEPT，特别是 W-M 规则，对这些团簇的适用性。对七元、八元和九元镓烷基金属的总势能表面（PES）的探索表明，绝对最小值具有 nido 型多面体排列。与较小的 Ga(n)H(n+2)（n = 4、5、6）不同，似乎簇的大小在很大程度上决定了其首选几何形状。尽管它们都没有封闭的（完全三角形）笼，但这些簇表现出显著的紧凑性，与硼烷双阴离子 B(n)H(n)（2-）相当，后者是 PSEPT 理论的原型。
