Professor Massimo Olivucci
Chemistry Department
Bowling Green State University
Bowling Green, OH

Monday, April 25, 2011
3:00 pm (CT)
3269 Beckman Institute

Abstract

During the last few years we have started to explore the possibility of designing and synthesizing molecules that could mimic the photoisomerization of the visual pigment Rhodopsin and, in particular its low-temperature photochromism [1]. When embedded in the opsin cavity the Rhodopsin chromophore (i.e. the protonated Schiff base of retinal) displays an ultrafast and stereoselective photoisomerization with high quantum yield. In order to design a chromophore displaying a similar efficiency in common solvents we have been looking at diverse alkylated Schiff bases featuring a single isomerizable double bond. In this lecture we show that the indanylidene-pyrroline (NAIP) framework [2-4] provides a computationally and synthetically viable prototype for the development of systems that reproduce the excited state electronic structure and photoisomerization dynamics of Rhodopsin in methanol or water. We will also show that, on the basis of these studies we have been able to achieve systems that, in perspective, can be used as electrostatic switches. In fact, we have been able 5to design an unprecedented “dipole” switch capable of inverting, reversibly, its ca. 15 D dipole moment upon double bond photoisomerization [5].