Computational study of the [(CO) 2 (benzoate)M II/III (terephthalate)] 0/1+ complexes with M = V, Cr, Mn, Fe and Co

Abstract

Computational study at DFT-B3LYP/LANL2DZ level of theory is carried out to evaluate structural, bonding and energetic characteristics of cis/trans isomers of the [(CO) 2 (benzoate)M II/III (terephthalate)] 0/1+ complexes with 3d transition metals M = V, Cr, Mn, Fe and Co. Results of this study show that all cis/trans isomers of these complexes in their two oxidation states are stable with distinctly different structures. As a general trend, for all cis/trans isomers of these complexes, the M–O(benzoate) and M–O(terephthalate) bonds are shorter for the M III oxidation state of the metal ion compared to those for the corresponding M II oxidation state. Also, structure of the set of four M–O bonds are almost asymmetric such that the optimized M II/III –O (terephthalate) bond lengths are slightly longer than the M II/III –O(benzoate) bond lengths. The coordination M–O bonds structure of the cis/trans isomers of the [(CO) 2 (benzoate)Co II (terephthalate)] complex have the most asymmetries, and interestingly, its trans isomer is more asymmetric than its cis isomer. The M III complexes have larger electric dipole moments compared to their corresponding M II complexes. Furthermore, cis/trans isomerization has no significant effect on the size of electric dipole moment for the M II complexes. © 2019 Elsevier B.V.