Dynamic NMR Analysis of Hindered Rotation in 7-Cis Retinyl Compounds

Abstract

The crux of visual excitation by light is the photoisomerization of 11-cis retinylidene Schiff base to its all-trans form--a configurational event which leads to the subsequent release of the chromophore from its apoprotein, opsin. The focus of the present study is the kinetic nature of dynamic rate processes involving retinal analogues in solution. Of primary concern are quantitative aspects of intramolecular rotation about the highly hindered C6-C7 sp2–sp2 hybridized single bond in a number of 7 -cis retinyl compounds.