9,11‐DIcis‐12‐FLUORORHODOPSIN. CHROMOPHORE PROPERTIES FROM 19F‐NMR STUDIES

Abstract
Abstract— From a 19F‐NMR study of 9,11‐dicis‐12‐fluororhodopsin and its photobleached product, we concluded that the initially formed chromophore retained its configuration and the photoproduct corresponded to the two‐bond isomerized all‐trans. Upon standing, it slowly isomerized to the 9‐cis isomer. The method represents a direct, non‐destructive procedure for determining configuration purity of the pigment formed. Its unique fluorine opsin shift value is consistent with the expected different orientation of the fluoro‐substituent in a dicis pigment.