An artificial molecular switch that mimics the visual pigment and completes its photocycle in picoseconds.
Single molecules that act as light-energy transducers (e.g., converting the energy of a photon into atomic-level mechanical motion) are examples of minimal molecular devices. Here, we focus on a molecular switch designed by merging a conformationally locked diarylidene skeleton with a retinal-like Schiff base and capable of mimicking, in solution, different aspects of the transduction of the visual pigment Rhodopsin. Complementary ab initio multiconfigurational quantum chemistry-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 infrared spectrum. These measurements indicate that a full cycle can be completed within 20 ps.
Sinicropi
Adalgisa
A
Dipartimento di Chimica, Università di Siena, via Aldo Moro 2, I-53100 Siena, Italy.
Martin
Elena
E
Ryazantsev
Mikhail
M
Helbing
Jan
J
Briand
Julien
J
Sharma
Divya
D
Léonard
Jérémie
J
Haacke
Stefan
S
Cannizzo
Andrea
A
Chergui
Majed
M
Zanirato
Vinicio
V
Fusi
Stefania
S
Santoro
Fabrizio
F
Basosi
Riccardo
R
Ferré
Nicolas
N
Olivucci
Massimo
M
D007536:Isomerism; D018716:Molecular Mimicry; D010777:Photochemistry; D012168:Retinal Pigments / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013997:Time Factors
D012168:Retinal Pigments