Novel porphyrazine derivative – 2,3,5,7,8,10,12,13,15,17,18,20-dodecaazaporphin and its complexes with M(II) ions of 3d-elements: DFT quantum-chemical modeling

Abstract

Using three different versions of the density functional theory (DFT) – B3PW91/TZVP, M06/TZVP and OPBE/TZVP chemical models, the calculation of the molecular structures of (6666) macrocyclic complexes of 3d-elements (M) with a novel (NNNN)-donor macrocyclic ligand, 2,3,5,7,8,10,12,13,15,17,18,20-dodecaazaporphin (H2L), was carried out. The values of the most important bond lengths, bond and non-bond angles in these metal complexes were presented. The standard enthalpy, entropy, and Gibbs energy of formation of these compounds were also calculated. It was noted that according to the data of the above chemical models, [MnL], [FeL], [CoL], [NiL], and [CuL] complexes with this novel ligand have a flat MN4 chelate node and a planar structure as a whole, while the [TiL], [VL], [CrL] and [ZnL] complexes have a non-coplanar MN4 chelate node. Moreover, all 6-membered rings in each of these metal chelates are identical to each other (both in terms of the sum of the bond angles included in them and in their assortment); adjoining 5-membered cycles for the majority of M are also identical to each other (non-identity is noted only in the cases M = Ti, Mn, as well as for the original 2,3,5,7,8,10,12,13,15,17,18,20-dodecaazaporphin). A good agreement was also noted between similar parameters calculated by various DFT methods, both qualitatively and quantitatively.