A QUANTUM-CHEMICAL THEORY OF TRANSITION-METAL DINITROGEN COMPLEXES

By applying the method of graph theory of molecular orbitals to the calculations ofstabilization energy, charge density, and bond order for mononuclear and binuclear as well astrinuclear dinitrogen complexes, we have obtained the following results: (i) For mononuclearand binuclear dinitrogen complexes the endocoordinated complexes are more stable than thosecoordinated in the side-on manner. For trinuclear complexes, on the other hand, those contain-ing both end-on and side-on coordinations are more stable than those containing end-on coordina-tions alone, within a wide range of energy parameter variations. (ii) In general, exo-nitrogenatoms carry more negative charge than endo-nitrogen atoms. (iii) The higher the energy levelof the d-orbital of the coordinated transition-metal atom is, the more negative the nitrogenatom will become.