DENSITY-FUNCTIONAL STUDY OF MONONITROSYLS OF FIRST-ROW TRANSITION-METAL ATOMS

The mononitrosyls of the transition metals of the third row of the per iodic table were calculated by means of the density functional theory. The geometries and frequencies of the MNO complexes in different stat es are reported. A bent geometry is found fur the systems with higher multiplicities from vanadium through copper and linear geometries for lower multiplicities. The binding mechanism is described through an an alysis of the molecular orbitals (MO). The bent geometry is obtained w hen the sigma antibonding MO resulting from the interaction of the 5 s igma MO of NO and the d(sigma), orbital of the metal center is occupie d. The electronic configuration of all complexes studied is presented in a diagram that allows one to predict qualitatively whether the comp lex is bent according to its multiplicity. The interaction of the tran sition metals with other diatomic molecules is briefly discussed. (C) 1997 American Institute of Physics.