Nature of the metal–carbon contacts in ene-diamido d0 metal complexes

Abstract

Folding of ene-diamido chelates in d⁰ metal complexes is generally attributed to a saturating π interaction of the metal with the central CC linkage. A MO analysis of selected models (DFT and EHMO levels) shows that the latter interaction is negligible (negative M–C overlap populations). Moreover, a detailed analysis of the orbital interactions highlights a two-electron flow from filled p_π orbitals of the nitrogen atoms toward the metal consequent to ligand folding. Conversely, it is evident that the CC π-electron cloud is only barely affected by the contacts with the metal atom.