Abstract
In order to investigate the effect of connector structure of diarylethene derivatives on the maximum absorption band, thermal stability, and fatigue resistance to photoirradiation, the photochromic compounds, 1,2-dicyano-1,2-bis(2,3,5-trimethyl-4-thienyl) ethene(DYE I) and 2,3-bis(2,3,5-trimethyl-4-thienyl) maleic anhydride(DYE II) were synthesized. The DYE I has cyano groups and the DYE II has anhydride groups on the 1,2 carbon position as connector group, respectively. Identification of synthesized photochromic dyes were performed with $^1H-NMR$ and FT-IR spectrophotometers. The properties of photochromic compounds synthesized were examined in toluene solution and dispersed in polystyrene film. Upon the introduction of cyclic structure to the connector group, the maximum absorption band $({\lambda}_{max})$ shifted to longer wavelength, and the thermal stability and fatigue resistance increased. It is reasoned that the change of an electron-accepting ability at the 1,2 positions of aromatic rings or the variations of conjugation length affect the physical and chemical properties of the diarylethene derivatives. And the thermal stability and the fatigue resistance properties were rather enhanced dispersed in polymer film than in the solution state on account of less oxidation.
