文摘
DFT calculations have been carried out on two series of closo clusters, namely M3(CO)9E2 and M4(CO)12E2 (M = Fe, Ru, Os; E = Bi, As, P, N, AsH+, PH+, NH+, S+, Se+, CH, SiH, BH–). Due to their mixed main-group/transition-metal nature, these clusters can a priori exhibit skeletal isomerism. Three different triangular bipyramidal arrangements are possible for compounds of the first series, whereas two different octahedral arrangements can be proposed for compounds of the second series. Calculations show that the relative energies of different skeletal isomers depend strongly on the nature of E. In particular, the following parameters play a crucial role: the E–E bond strength, the size of E, the repulsion between the E lone pairs when both E units are bare atoms, the E electronegativity and the preference for sp3 hybridization in the case of E = CR, NR, and PR. To cite this article: N. Guechtouli et al., C. R. Chimie (8) 2005.
