Stabilization of unusual metal oxidation state +4 in the iron, cobalt, nickel, and copper complexes with trans-di[benzo]porphyrazine and two fluoride anions: a DFT quantum chemical analysis

Abstract

Molecular structure calculations of heteroligand (6666)macrotetracyclic metal (MIV) chelates (M = Fe, Co, Ni, Cu) with trans-di[benzo]porphyrazine as the (N,N,N,N)-donor ligand and two F− anions were carried out at the OPBE/TZVP level of density functional theory. The key bond lengths, bond angles, and non-bond angles in the complexes were determined and corresponding standard enthalpies, entropies, and Gibbs energies of formation were calculated. All complexes have slightly distorted tetrahedral structures. The complex-forming agent MIV lies in the plane formed by the donor nitrogen atoms. The metal—nitrogen bonds are usually pair-wise equal. The six-membered metal chelate rings in the complexes are identical to one another from the standpoint of both the sum and set of the bond angles.