Comparative DFT Study of the  M-L Binding Energies  (M = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn; L = Porphine, P, and P4-Substituted Porphine, P(P)4)

File uploaded by Aleksey Kuznetsov on Sep 12, 2015
Version 1Show Document
  • View in full screen mode

We performed comparative DFT study of the binding energies between the first-row transition metals M (M = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn) and two ligands of the similar type: porphine, P, and its completely P-substituted counterpart, P(P)42-, using several density functionals and the split-valence polarized 6-31G* basis set. We studied both neutral, M2+-L, and cationic, M3+/4+-L, species. The main findings of our research summarize as follows: complete substitution of all the pyrrole nitrogens with P-atoms generally does not affect the ground spin state of metalloporphyrins; (ii) generally, for the MP(P)4 compounds calculated ****/LUMO gaps and optical gaps are smaller than for their MP counterparts; (iii) the trends in the changes of the binding energies between Mn+ and P(P)42-/N42- are very similar for both ligands (see Figure 1 for the M2+-L binding energies). The complete substitution of the pyrrole nitrogens by the P-atoms generally decreases the Mn+ - ligand binding energies. All the MP(P)4 compounds studied are stable according to the calculated Ebind values and therefore can be potentially synthesized.