Probing the electronic structure, chemical bonding, and excitation spectra of [CuE]+/0/- (E=14 group element) diatomics employing DFT and ab initio methods

The electronic structure, chemical bonding, and excitation spectra of neutral, cationic, and anionic diatomic molecules of Cu and 14 group elements formulated as [CuE]+/0/- (E = C, Si, Ge, Sn, Pb) were investigated by density functional theory (DFT) and time-dependent (TD)-DFT methods. The electronic and bonding properties of the diatomics analyzed by natural bond orbital (NBO) analysis approch revealed a clear picture of the chemical bonding in these species. The spatial organization of the bonding between Cu and E atoms in the [CuE]+/0/- (E = Si, Ge, Sn, Pb) molecules can easily be recognized by the cut-plane electron localization function representations. Particular emphasis was given on the absorption spectra of the [CuE]+/0/- which were simulated using the results of TD-DFT calculations employing the hybrid Coulomb-attenuating CAM-B3LYP functional. The absorption bands have thoroughly been analyzed and assignments of the contributing principal electronic transitions associated to individual excitations have been made. (c) 2012 Wiley Periodicals, Inc.