Spectral manifestation of distorted forms metalloporphyrins at low temperatures

Abstract

Different spectral forms of a set of metalloporphyrins with Mg (II), Zn (II), Pd (II) and Pt (II) ions in solid solutions (Shpol'skii matrices, solid tetrahydrofuran and solid rare gas matrices) have been detected in the absorption and luminescence spectra at cryogenic temperatures. The spectral manifestation of a planar form, as well as two distorted forms for Mg- and Zn-porpyrins was formed in the ground electronic state at low temperatures. An existence of two spectral forms of Pd and Pt-porphyrins was observed in their phosphorescence spectra. In the case of Mg-porphyrin the spectral shift between positions of 0-0 transitions the planar and first distorted spectral forms is about 220 cm -1 .