Photophysics and photochemistry of 2,6-distyrylpyridine and some heteroanalogues

Abstract

The photophysical and photochemical properties of some symmetric (E,E)-2,6-di(arylvinyl) derivatives of pyridine, where the side aryl groups were phenyl, pyridyl, furanyl, thienyl and thiazolyl were investigated. The conformational equilibria between the two more abundant rotamers and their role in the kinetic competition between the radiative and reactive (E,E→E,Z) relaxation channels of their lowest excited singlet state are described and compared with those of the parent hydrocarbon, 1,3-distyrylbenzene. The effect of intramolecular hydrogen bonds between the nitrogen atom and the ethenic hydrogens on the nature and properties of the S₁ state is discussed.