Model analysis of branching photoreactions with conformationally flexible intermediate

The principal model of multistage branching photoreaction with conformationally flexible intermediate is analyzed. The consideration is restricted to the case of ground-state conformational control. A violation of the reciprocity low as applied to the reactions with alternating photo and dark processes is emphasized. Applications to the reactions of monomolecular photoisomerization of abundant compounds with triene chromophore are discussed. In the specific case of the previtamin D photosynthesis the ways of purposeful influence on the pathway and the products yield of the reaction are exposed. In particular, opportunities connected with an influence on the conformational equilibrium and with the use of high intensity laser irradiation, as well as the possibilities of the temperature control are considered.