HOMOGENEOUS PHOTODIMERIZATION AND THERMAL BACK-REACTION OF A STYRYLPYRYLIUM TRIFLATE

The work reported here demonstrates for the first time a forward and r everse topochemical, single-crystal-to-single-crystal reaction. By ful l crystal structure analysis of the product and substitutional crystal s of intermediate conversion, it is proven that the forward topochemic al photodimerization proceeds homogeneously through a solid solution o f monomer and dimer over the entire range of conversion. The photoreac tion is shown to be driven homogeneously or heterogeneously through ch oice of irradiation conditions.