Synthesis, spectral, electrochemical and flash photolysis studies of Fe(II), Ni(II) tetrapyridylporphyrins coordinated at the periphery with chromium(III) phenanthroline complexes

[FeTPyP(Crphen(2)Cl)(4)][PF6](8) and [NiTPyP(Crphen(2)Cl)(2)][PF6](8), where TPyP = 5,10,15,20- tetra-(4-pyridyl) porphyrin and phen = 1,10-phenanthroline, preparations are communicated. The complexes were characterized by UV-Vis spectroscopy, cyclic voltammetry, UV-Vis spectroelectrochemistry, elemental analysis, FT-IR, and MALDI-TOF mass spectrometry. Their photochemical reactions were investigated with the flash photolysis technique. The complexes exhibit a rich electrochemistry which includes a cathodic quasireversible process, i.e., the Cr(III)/Cr(II) couple, and two cathodic processes consistent in the sequential transfer of two electrons to the metalloporphyrins center. Porphyrin-centered excited states are generated in the flash irradiation (lambda(exc) = 351 nm) of either complex. These states are converted to other excited states or intermediates. The intermediates react with oxidants, Ru(NH3)(6)(3+), and reductants, I, TEOA, and alcohols. Charge separated intermediates or excited states with LMCT character account for the photoreactions. (C) 2012 Elsevier B. V. All rights reserved.