Photochemistry of a crown ether styryl dye adsorbed on silica gel and in acetonitrile solution: a comparative flash photolysis study

Abstract

The photochemical behaviour of a photochromic crown ether styryl dye (BOB) adsorbed on silica gel has been found by a steady-state technique to be similar to that observed in a fluid solution of high polarity. The intermediate spectra obtained by diffuse reflectance laser flash photolysis of BOB on silica gel in a nitrogen atmosphere have been preliminarily attributed to the triplet-triplet (T-T) absorption of BOB and the absorption of BOB cation radicals. For comparison, the absorption spectrum of BOB triplets with a lifetime of ∼0.8 μs in acetonitrile solution has been obtained using biphenyl as a sensitizer.