Abstract

Novel spiro[thioxanthene-naphthopyrans] were prepared and their photochromic properties in solution investigated under UV-Vis continuous irradiation. When compared to known similar naphthopyrans these new compounds showed a significant bathochromic shift of the maximum wavelength of absorption and faster ring closure kinetics.

Keywords: Photochromism, naphthopyran, spiro compounds, kinetics, UV irradiation, heterocycles