Evidence of significant covalent bonding in Au(CN)(2)(-)

Xue-Bin Wang; Yi-Lei Wang; Jie Yang; Xiao-Peng Xing; Jun Li; Lai-Sheng Wang

doi:10.1021/ja908106e

Evidence of significant covalent bonding in Au(CN)(2)(-)

J Am Chem Soc. 2009 Nov 18;131(45):16368-70. doi: 10.1021/ja908106e.

Authors

Xue-Bin Wang¹, Yi-Lei Wang, Jie Yang, Xiao-Peng Xing, Jun Li, Lai-Sheng Wang

Affiliation

¹ Department of Physics, Washington State University, 2710 University Drive, Richland, Washington 99354, USA.

PMID: 19860420
DOI: 10.1021/ja908106e

Abstract

The Au(CN)(2)(-) ion is the most stable Au compound known for centuries, yet a detailed understanding of its chemical bonding is still lacking. Here we report direct experimental evidence of significant covalent bonding character in the Au-C bonds in Au(CN)(2)(-) using photoelectron spectroscopy and comparisons with its lighter congeners, Ag(CN)(2)(-) and Cu(CN)(2)(-). Vibrational progressions in the Au-C stretching mode were observed for all detachment transitions for Au(CN)(2)(-), in contrast to the atomic-like transitions for Cu(CN)(2)(-), revealing the Au-C covalent bonding character. In addition, rich electronic structural information was obtained for Au(CN)(2)(-) by employing 118 nm detachment photons. Density functional theory and high-level ab initio calculations were carried out to understand the photoelectron spectra and obtain insight into the nature of the chemical bonding in the M(CN)(2)(-) complexes. Significant covalent character in the Au-C bonding due to the strong relativistic effects was revealed in Au(CN)(2)(-), consistent with its high stability.