DINITROGEN ACTIVATION BY DIRUTHENIUM COFACIAL DIPORPHYRIN COMPLEX. DFT STUDY

Density functional theory and ab initio calculations are used to study the activation of dinitrogen by diruthenium cofacial diporphyrin complex [Ru2DPB(Im)2] (DPB= diporphyrinato-biphenylene tetraanion and Im= imidazole). The calculated equilibrium geometry of the formed complex [( -N2)Ru2DPB(Im)2] was found to involve the flaring out of the diporphyrin’s rings with a nearly linear dinitrogen bridge. The subsequent detailed analysis of the molecular orbitals (MOs) of this complex allows one to conclude that the dinitrogen activation is realized due to both the donation from the dinitrogen occupied bonding -MO to unoccupied d-AOs of the Ru atoms and the two-orbital back donation from two occupied MOs of the complex [Ru2DPB(Im)2] to the two splitting components of the unoccupied antibonding *-MO of N2.