Solvent dielectric effects on isomerization dynamics: Investigation of the photoisomerization of 4,4rsquo;hyphen;dimethoxystilbene andthyphen;stilbene innhyphen;alkyl nitriles

摘要

New data for the photoisomerization dynamics ofthyphen;stilbene and 4,4rsquo;hyphen;dimethoxystilbene in polar solvents are reported. These data demonstrate that innhyphen;alkyl nitriles, nonassociated polar solvents, it is possible to extract a solvated barrier for the isomerization. This result is contrasted with recent studies innhyphen;alkyl alcohols, associated polar solvents, where this separation is not possible and clarifies the origin of the changing barrier height innhyphen;alkyl alcohols. Comparison of reduced isomerization rates with models of chemical reaction dynamics in solution are drawn. Good agreement of the data with a coupled oscillator model is found.