Au(η2-Sn2Sb2)23-: a Mixed Group 14/15 Tetrahedral Dimer Bridged by Au

摘要

A new ternary cluster anion [Au(η~2-Sn_2Sb_2)_2]^(3-) was synthesized and identified. The electronic structure of [Au(η~2-Sn_2Sb_2)_2]^(3-) was analyzed by means of DFT calculations. The electronic energy and energy gap indicate that [Au(η~2-Sn_2Sb_2)_2]^(3-) features coplanar faces AuSn_2 in which gold is directly coordinated by four tin atoms. Molecule orbital composition analysis indicates that d-orbital in Au atom contributes to bonding. Charge decomposition analysis(CDA) shows that electron donation and back donation are the key factors forming planar conformation of Au atom in [Au(η~2-Sn_2Sb_2)_2]^(3-). Meanwhile, the calculated Mayer bond order indicates relatively weaker interactions between Au and coordinated tetrahedral [Sn_2Sb_2]^(2-).