Abstract

We performed first systematic DFT study of the structures and electronic features (frontier orbitals energies, HOMO/LUMO and optical gaps, IPs and EAs) of the MP(P) 4 compounds, with increasing number of d-electrons: 3d(1)4s(2) (Sc) > 3d(2)4s(2) (Ti) > 3d(6)4s(2) (Fe) > 3d(8)4s(2) (Ni) > 3d(10)4s(1) (Cu) > 3d(10)4s(2) (Zn). We performed systematic comparison with the tetrapyrrole MP counterparts. Complete substitution of the pyrrole nitrogens by P-atoms does not change the calculated ground spin state of the compound. All the MP(P)(4) species adopt a bowl-like shape, compared to generally planar or slightly distorted shapes of their MP counterparts. Significant positive charge accumulates on P-atoms in MP(P)(4). Positive charges on the metals in MP(P)(4) are noticeably lower than in the MP counterparts. The calculated MP(P)(4) HOMO/LUMO gaps and optical gaps are noticeably smaller than the corresponding gaps in their MP counterparts, which is explained by stabilization of the MP(P)(4) LUMOs. (C) 2014 Elsevier B.V. All rights reserved.