Luminescent switch: Synthesis, characterization, and properties of some europium-based dithienylethenes

Some europium-based dithienylethenes have been synthesized and their structures have been confirmed by IR spectroscopy and elemental analysis. The photochromic properties and luminescent behaviors of these compounds in solution have been measured upon irradiation with UV or visible light. UV/vis absorption and luminescence spectra indicated that these dithienylethenes displayed obvious photochromism and luminescent switching properties. Specially, when compared with other europium-based dithienylethenes, the triphenylamine and terpyridyl-based dithienylethene showed the photocyclization-dependent ratiometric luminescent switch behavior.