title: An artificial molecular switch that mimics the visual pigment and completes its photocycle in picoseconds.
abstract: 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.
authors.affiliation: Dipartimento di Chimica, Università di Siena, via Aldo Moro 2, I-53100 Siena, Italy.
authors.forename: Adalgisa
authors.initials: A
authors.lastname: Sinicropi
authors.forename: Elena
authors.initials: E
authors.lastname: Martin
authors.forename: Mikhail
authors.initials: M
authors.lastname: Ryazantsev
authors.forename: Jan
authors.initials: J
authors.lastname: Helbing
authors.forename: Julien
authors.initials: J
authors.lastname: Briand
authors.forename: Divya
authors.initials: D
authors.lastname: Sharma
authors.forename: Jérémie
authors.initials: J
authors.lastname: Léonard
authors.forename: Stefan
authors.initials: S
authors.lastname: Haacke
authors.forename: Andrea
authors.initials: A
authors.lastname: Cannizzo
authors.forename: Majed
authors.initials: M
authors.lastname: Chergui
authors.forename: Vinicio
authors.initials: V
authors.lastname: Zanirato
authors.forename: Stefania
authors.initials: S
authors.lastname: Fusi
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Santoro
authors.forename: Riccardo
authors.initials: R
authors.lastname: Basosi
authors.forename: Nicolas
authors.initials: N
authors.lastname: Ferré
authors.forename: Massimo
authors.initials: M
authors.lastname: Olivucci
mesh_terms: D007536:Isomerism; D018716:Molecular Mimicry; D010777:Photochemistry; D012168:Retinal Pigments / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013997:Time Factors
chemical_list: D012168:Retinal Pigments