PICOSECOND AND NANOSECOND TSOMERIZATION KINETICS OF PROTONATED 11‐CIS RETINYLIDENE SCHIFF BASES

Abstract— Picosecond and nonosecond spectroscopy has been used to study the isomerization mechanism of protonated 11‐cis retinylidene Schiff bases. The formation and bleaching of absorption bands within 10 ps and corresponding decay and recovery within 11 ns indicate that the isomerization mechanism of the protonated Schiff bases is not identical to rhodopsin in which the primary photophysical event is probably due to electron transfer or partial isomerization of the chromophore to a nonplanar conformation.