Bridging gold: B‐Au‐B three‐center‐two‐electron bonds in electron‐deficient B2Aun−/0 (n = 1, 3, 5) and mixed analogues |
| |
Authors: | Wen‐Zhi Yao Da‐Zhi Li Si‐Dian Li |
| |
Affiliation: | 1. Institue of Molecular Science, Shanxi University, Taiyuan 030001, Shanxi, People's Republic of China;2. Institute of Materials sciences and Department of Chemistry, Xinzhou Teachers' University, Xinzhou 034000, Shanxi, People's Republic of China |
| |
Abstract: | A systematic density functional theory and wave function theory investigation on the geometrical and electronic structures of the electron‐deficient diboron aurides B2Au (n = 1, 3, 5) and their mixed analogues B2HmAu (m + n = 3, 5) has been performed in this work. Ab initio theoretical evidences strongly suggest that bridging gold atoms exist in the ground states of C2v B2Au?(1A1), C2 B2Au(1A), C2v B2Au3(2B1), C2v B2Au(1A1), and Cs B2Au5(2A″), which all prove to possess a B? Au? B three‐center‐two‐electron (3c‐2e) bond. For B2HmAu (m + n = 3, 5) mixed anions, bridging B? Au? B units appear to be favored in energy over bridging B? H? B, as demonstrated by the fact that the Au‐bridged C2v B2H2Au? (1A1), Cs B2HAu (1A′), and C1 B2HAu (1A) lie clearly lower than their H‐bridged counterparts Cs B2H2Au? (1A′), C2 B2HAu (1A), and C2v B2HAu (1A1), respectively. Orbital analyses indicate that Au 6s makes about 92–96% contribution to the Au‐based orbitals in these B‐Au‐B 3c‐2e interactions, whereas Au 5d contributes 8–4%. The adiabatic and vertical detachment energies of the concerned anions have been calculated to facilitate their future experimental characterizations. The results obtained in this work establish an interesting 3c‐2e bonding model (B? Au? B) for electron‐deficient systems in which Au 6s plays a major role with non‐negligible contribution from Au 5d. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2011 |
| |
Keywords: | diboron aurides bridging gold 3c‐2e bonds ab initio calculations structures properties |
|
|