Synthesis and characterization of excited state intramolecular proton transfer based 2-hydroxylaryl imidazole fluorescent materials

Excited state intramolecular proton transfer (ESIPT) based highly soluble, thermally stable fluorescent molecules namely 2-(1-butyl-4,5-diphenylimidazol-2-yl)phenol (1) and 2-(1-(4-(dimethylamino)phenyl)-4,5-diphenylimidazol-2-yl)phenol (2) were synthesized. These molecules were investigated by experimental as well as quantum mechanical techniques. Thin films of 1 and 2 were prepared using spin coating and thermal evaporation techniques onto glass substrates kept at room temperature and characterized for their structural, photo physical and electrical properties. UV–vis absorption studies showed that imidazole molecules preferred H-type aggregation in thin film form. Synthesized molecules showed almost the similar blue emission peaks in solution as well as thin films.

Two novel non-planar, thermally stable, highly soluble, ESIPT based blue emitting imidazole derivatives (1) and (2) have been synthesized and characterized in solution and thin film states.Figure optionsDownload as PowerPoint slideHighlights
► Synthesis of ESIPT based 2-hydroxyaryl imidazole as blue emitters.
► Compounds are suitable for soluble processing and thermal evaporation.
► Formation of amorphous thin films with H-aggregation.
► Compounds show the similar blue emission in solution and thin films.