A quantum chemical study of the molecular structure of zinc(II) and boron(II) complexes with monoiodo and dibromo substituted dipyrrines

The geometric parameters of the molecular structures of 4-monoiododipyrrine, 4,4′- and 5,5′-dibromodipyrrine complexes with zinc(II) and boron(III) of the composition [ZnL2] and [BF2L] respectively are determined at the M06 and B3LYP levels of density functional theory with the Def2-SVP basis set. The lengths of Zn–N, B–N, and B–F coordination bonds, N–X–N, F–B–F, C–C–C bond angles, the dihedral angles between the planes of pyrrole rings in the dipyrrine ligand, dipyrrine planes in [ZnL2], dipyrrine core and the plane passing through the atoms of the BF2 group are optimized. The effect of structural factors on the geometric parameters and the widths of the HOMO–LUMO energy gap in halogen substituted dipyrrinates is analyzed.