Magnetic circular dichroism studies. Part 45. A comparison between the magnetic circular dichroism and Shpol'skii spectra of palladium, zinc, and magnesium porphin

Abstract

Eleven vibronic bands have been identified by curve fitting procedures in the low temperature m.c.d. spectra of palladium, zinc, and magnesium porphin. These bands correspond closely to the predominant lines in the Shpol'skii spectra, although differences in complexation states exist between the glass and polycrystalline matrices. Based upon the sign of the m.c.d. A terms and their intensity changes with changes in the oscillator strength of the Q(O,O) band all vibronic bands could be assigned to a_1g, a_2g, b_1g, and a_2g, modes. The Q(O,O) band in magnesium porphin is of very low intensity and exhibits an A term of opposite sign compared to that reported as yet for other metallo porphins.