Selective photoconversion of photochromic diarylethenes and their properties

Abstract

Selective photoconversions of photochromic diarylethene derivatives has been described using diarylethene derivative 1a as a model compound. Upon irradiation with 254 nm light, 1a undergoes photocyclization to yield the ring-closed isomer 1b in the absence of oxygen, or is transformed to the thiolactone derivative 1c in the presence of oxygen (in the air), respectively. It was found that 1b can be reversed back to 1a with visible light irradiation, the ring-opening and ring-closing photoswitch can be performed in the absence of oxygen. 1c is, however, photo-inactive and cannot be reversed back to 1a with UV or visible light irradiation. It was also found that 1c shows fluorescence whereas both 1a and 1b show no fluorescence.