Low temperature optical spectra of Zn porphin in triphenylene

Abstract

The low temperature optical absorption spectra of single crystals of triphenylene doped with Zn porphin have been observed in detail. The spectra consisted of sharp lines, many of which were polarized. This is thought to be the first direct observation of polarized sharp line spectra of a porphyrin. Also observed were a number of weak anomalous absorption lines near the 0–0 transition, but at longer wavelengths. Two different site models were proposed to account for the polarization properties of the spectra. The implication of these results in the interpretation of porphyrin spectra are discussed.