NATURE OF M^δ+···δ+C-O^δ- INTERACTIONS IN METAL CARBONYLS. AN ELECTRONIC STUDY BASED ON THE TOPOLOGY OF THE ELECTRON CHARGE DENSITY DISTRIBUTION AND ITS LAPLACIAN FUNCTION

The nature of the metal-ligand interactions, in the [Ti(CO)₆]^2-, [V(CO)₆]^-, [Cr(CO)₆], [Mn(CO)₆]⁺, [Fe(CO)₆]²⁺ and [Co(CO)₆]³⁺ complexes has been studied by means of topological analyses of the electron charge density, using the Quantum Theory of Atoms in Molecules (QTAIM) and Electron Function Localization (ELF). The calculations were made using B3LYP method with the 6-311++G(2d,2p) basis set. The results show that the charge transferences (both σ-donation and π-backbonding) and the electrostatic interaction between the lone pair of C atom of the CO molecule and nucleus of the metal species play a key role in stabilizing of these metal complexes. Finally, we have found QTAIM parameters that explaining the nature of the M^δ+•••^δ+C-O^δ- interactions in metal carbonyls.

Keywords:
Laplacian; QTAIM; coordination complexes; dative covalent bond