Study of ligand effects in aurophilic interactions using local correlation methods

Abstract

In this study, we present a series of calculations on Au(I) dimer complexes, investigating the interactions in play through the use of local correlation methods. The focus is placed on the impact of ligand effects in the interaction energy. Aurophilicity (the interaction between the closed shell Au(I) cationic centers) is commonly considered to be the major driving force for dimer formation. However, our calculations show that weak interactions between ligands can dominate even in relatively small complexes. This, in turn, can lead to an ambiguous ordering of the metallophilicity of Group 11 elements. We propose an unbiased separation of the metal–metal interaction through the use of local correlation and orbital population analysis. The latter reveals a constant energy profile for a variety of complexes which could in turn be used for the analysis of d¹⁰–d¹⁰ interactions in more complex systems.