Substituent position effect on the optoelectronic properties of photochromic diarylethenes

Photochromic diarylethenes bearing fluorine atoms at the ortho-, meta-, or para-position of both terminal phellyl rings have been synthesized. Effect of the substituent positions on their optoelectronic properties, including photochromism ill solution, fluorescence, and electrochemical properties were investigated for the first time. The results indicated that the position of the fluorine substituent had remarkable impacts oil molar absorption coefficient of the closed-ring forms of diarylethenes, quantum yields of the cyclization and cycloreversion reactions, fluorescence intensity, as well as the oxidation potential. (c) 2006 Elsevier Ltd. All rights reserved.