Choice of Coordination Number in d1° Complexes of Group 11 Metals.

The distribution of di-, tri-, and tetracoordination among the d10 ions of the group 11 metals is theoretically analyzed by means of density functional calculations on more than 150 model complexes of general formula [MXmLn](1-m) (where M = Cu, Ag, or Au; L = NH3 or PH3 X = Cl, Br, or I; m + n = 2-4). The energy of a ligand association reaction has been found to be practically determined by two contributions: the interaction energy and the energy of deformation of the metal coordination sphere. The larger deformation energy of gold complexes compared to copper and silver ones explains the predominance of dicoordination among AuI complexes, in comparison with CuI and AgI, for which dicoordination is far less common than tri- and tetracoordination. Other experimental trends can be explained by looking at the fine details of these two energetic components. [ABSTRACT FROM AUTHOR]