Photochromic behavior of 2,3-bis(2,5-dimethylthiophene-3-yl)thiophene-5-carbaldehyde oxime.

Photochromic diarylethene oxime isomers were obtained by coupling between hydroxylamine hydrochloride and 2,3-bis(2,5-dimethylthiophene-3-yl)thiophene-5-carbaldehyde. The two isomers were confirmed by NMR. Photochromic behavior was investigated in THF. Reversible photochromism could be induced by alternated UV/Visible light. The solution color also can be toggled between colorless and light purple. Corresponding photo- and thermo-stability measurements indicate that they are stable in the dark at room temperature. However, the degradation of the two isomers is accelerated with the temperature rising and prolonged exposure to UV light. Optimized geometry structure and frontier molecular orbitals further supported their photochromic activity. [ABSTRACT FROM PUBLISHER]