COORDINATION OF NO2 TO CU AND MG IN M(NO2)(2) COMPLEXES - A THEORETICAL-STUDY

The geometries, vibrational frequencies, and metal-ligand bond dissoci ation energies of 18 different structures of the Cu(NO2)(2) complex ha ve been studied. Mg(NO2)(2) and Cu(NO3)(2) have also been studied for comparison. The most stable structure of Cu(NO2)(2) and CuO(NO3)(2) co rresponds to a D-2h one with a coplanar eta(2)-O,O coordination for th e two NO2 ligands. For Mg(NO2)(2) the most stable structure is a D-2d one. The bonding in the D-2h and D-2d structures of Cu(NO2)(2) is anal yzed. For the MNO2 systems the binding energy is very similar with bot h metals, while for the M(NO2)(2) complexes the difference when changi ng the metal is very important. This behavior is related to the first and second ionization potentials of Cu and Mg. The computed vibrationa l frequencies are in good agreement with the available experimental da ta.