Electronic and geometrical structures of nitroso ligands coordinated to transition-metal atoms. A nonempirical theoretical study of bis(phosphino)(nitrosotrifluoromethane)platinum and bis(phosphine)(nitrosomethane)platinum

The modifications of the molecular geometry and electronic structure of CF3NO and CH3NO caused by coordination to a Pt(0) center have been studied by means of nonempirical MO-LCAO theoretical calculations on the model complexes Pt(PH3)2(RNO). The η2 coordination mode of RNO, in which the N-O group acts as a side-on σ-donor and π-acceptor, is found to be more favorable than the η1 mode, in which only the N atom directly interacts with the metal center. The bonding characteristics of the RNO ligands are compared with those of the isoelectronic dioxygen ligand by investigating the electronic structure of the Pt(PH3)2(η2O2) complex.