An artificial molecular switch that mimics the visual pigment and completes its photocycle in picoseconds
Single mols. that act as light-energy transducers (e.g., converting the energy of a photon into at.-level mech. motion) are examples of minimal mol. devices. Here, we focus on a mol. switch designed by merging a conformationally locked diarylidene skeleton with a retinal-like Schiff base and capable of mimicking, in soln., different aspects of the transduction of the visual pigment Rhodopsin. Complementary ab initio multiconfigurational quantum chem.-based computations and time-resolved spectroscopy are used to follow the light-induced isomerization of the switch in methanol. The results show that, similar to rhodopsin, the isomerization occurs on a 0.3-ps time scale and is followed by <10-ps cooling and solvation. The entire (2-photon-powered) switch cycle was traced by following the evolution of its IR spectrum. These measurements indicate that a full cycle can be completed within 20 ps.
Keywords: Molecular modeling; Molecular switches; Simulation and Modeling (artificial mol. switch mimics visual pigment and completes photocycle in picoseconds); Isomerization (photoisomerization; artificial mol. switch mimics visual pigment and completes photocycle in picoseconds); Pigments (visual; artificial mol. switch mimics visual pigment and completes photocycle in picoseconds) ; mol switch vision pigment photocycle isomerization
Dipartimento di Chimica,Universita di Siena,Siena,Italy.
written in English.
1097665-20-7; 1097665-22-9 Role: BSU (Biological study, unclassified), PRP (Properties), BIOL (Biological study) (artificial mol. switch mimics visual pigment and completes photocycle in picoseconds)
Record created on 2009-03-18, modified on 2016-08-08