Synthesis of new benzylpyridines as potential photochromic compounds

Photoinduced proton transfer systems such as 2-(2 ' ,4 ' -dinitrobenzyl)pyr idine derivatives have been developed in an attempt to apply the compounds to variable optical transmission materials. However their fatigue resistanc e property is a limitation for these applications. Mew benzylpyridines have been synthesized and tested. 2-(2 ' ,4 ' -Diphenylsulfonybenzyl)pyridine w as found to be photochromic in the crystalline state and in ethanolic solut ion (lambda (max)= 485 nm) upon UV flash photolysis.