Porphyrin Complexes with p,d, and fMetals in High Oxidation States: Structures,Electronic Absorption,and IR Spectra

This paper is a review of data obtained by the authors and of the literature data on the molecular structure of porphyrin complexes with p, d, and f metals in oxidation states from two to five and on complexation as revealed from the absorption spectra of porphyrins in UV, visible, and IR regions. It was shown that, depending on the type of donor–acceptor bonds, the EAS of metalloporphyrins can be divided into three groups and classified as common, hypso, or hyper spectra. The high-frequency or low-frequency shifts of bands of metal-sensitive porphyrin vibrations in IR spectra of complexes correlate with the type of electronic spectrum; therefore, they were used to study the electronic aspects of coordination interaction in the porphyrin complexes.