Influences of the substituents on the Cr=C bond in [(OC)5Cr=C(OEt)-para-C6H4X] complexes: quantum Theory of Atoms in Molecules, Energy Decomposition Analysis, and Interacting Quantum Atoms

This study was conducted to investigate the effect of various substituents on the Cr=C bond in the [(OC)(5)Cr=C(OEt)-para-C6H4X] complexes using B3LYP*-based quantum mechanical calculations. In this respect, the study evaluates the influence of electron withdrawing and donating groups on the Cr=C bond distances and topological properties and correlates the calculated parameters with the Hammett and Brown constants for the para-substituted (sigma(p) and sigma, respectively) functional groups. Also, the frontier orbital analysis was used to show the electronic structure of complexes and the percentage composition in terms of the defined groups of frontier orbitals was evaluated. To obtain insight into the physical nature of Cr=C bond bonds, we extensively used energy decomposition analysis and Bader's Quantum Theory of Atoms-in-Molecules (QTAIM). With this aim, in addition to examining the bond critical points properties, we apply Pendas' Interacting Quantum Atoms (IQA) scheme, which enables the rigorous and physical study of Cr=C bonds in these complexes. [GRAPHICS]