Document Type: Original Research Paper
East Tehran branch of Islamic azad university
Department of Chemistry, Central Tehran Branch, Islamic Azad University, Tehran, IRAN
In the present research, the electronic structure and bonding properties of the Cr(CO)3L complexes (L= 6-benzne, 6-garphyne) was studied with MPW1PW91 quantum chemical computations. Quantum theory of atoms in molecules (QTAIM) was applied to elucidate these complexes Cr-CO bonds. The ellipticity () and values of the Cr-CO bonds were calculated. The amount of p-d back-donation of Cr-CO bonds were illustrated by calculation of the magnitude of the quadrupole polarization of carbon atom. Delocalization index values of C-C bonds of the six-member rings was calculated. Percentage composition in terms of the specified groups of frontier orbitals was found for these complexes to investigation of the feature in metal-ligand bonds. The nature of chemical bond between the -ring and Cr(CO)3 fragments was demonstrated through energy decomposition analysis (EDA). Frontier orbital analysis reveals that maximum contributions for HOMO and LUMO are the largest contribution of HOMO and LUMO arises from graphyne ligand in Cr(CO)3(6-graphyne) complex. EDA analysis reveals that interaction of benzene and Cr(CO)3 is stronger than graphyne with Cr(CO)3. Based on the results of the QTAIM analysis, there is a mixture of two parameters of the closed-shell and shared for Cr-CO bonds. The increase in quadrupole polarization values in the complexes compared to free CO values show the p-d back-donation in Cr-CO bonds.