First-principles study of electronic structures of hexa- and dodecanuclear silver clusters coordinated with organic ligands

Understanding to the stability of polynuclear metal ions is crucial in the design and synthesis of novel hybrid organic–inorganic materials. In this study, the geometrical and electronic properties of positively charged hexa- and dodeca-nuclear Ag clusters with various organic ligands are studied by means of density functional theory calculations. The structures of Ag clusters and their interaction with ligands are analyzed in terms of their geometries, charge redistribution, energetics, etc. To overcome electrostatic repulsion among the Ag ions, a special structure is formed for the Ag clusters in which the atoms bond both to the ligands and to each other. We reveal that the stability of the Ag clusters stems mainly from charge compensation from the ligands, geometrical constraint by the ligands and multiple argentophilic AgAg interactions within the Ag clusters.