On the electronic structure and bonding of the polynuclear aryl derivatives of the group IB metals Cu5(C6H5)5, Ag4(C6H5)4 and Au5(C6H5)5 by density functional theory

Density functional calculations are carried out on the Cu5(C6H5)5, Ag4(C6H5)4 and Au5(C6H5)5 systems. Electronic structure and bonding aspects of the interaction between the Mn and (C6H5)n units are investigated. Calculations are performed on the corresponding naked clusters of four and five metal atoms in order to study the M-M bond and the stability trend as a function of cluster size. The following conclusions are reached: (i) M-M bonding is present in all the complexes (both naked and with phenyls) and (ii) the stability increases with cluster size, even if, for the complexes with phenyls, tetramers and pentamers show a comparable stability. Relativistic effects turn out to be essential for the description of gold systems but not remarkable for silver and copper clusters.