title: Photoelectrochromism in the Retinal Protonated Schiff Base Chromophore: Photoisomerization Speed and Selectivity under a Homogeneous Electric Field at Different Operational Regimes.
abstract: The spectral tunability, photoisomerization efficiency and selectivity, of the native all-trans retinal protonated Shiff base (PSB) chromophore driven by a homogeneous electric field is systematically investigated. By analyzing the absorption wavelength dependence, charge distribution, and PES profiles along selected torsional angles, as well as the electronic structure, energetics, and topography of the CI seam in the presence of strong positive and negative electric fields, we recognize the existence of qualitatively/fundamentally different photophysics and photochemistry with respect to the unperturbed (i.e., absence of an electric field) chromophore. We rationalize the findings within the scope of molecular orbital theory and deliver a unified picture of the photophysics of the retinal PSB chromophore over a wide, even beyond the usually observed, spectral regime, ranging from the near-infrared to the ultraviolet absorption energies. This work has a 3-fold impact: a) it accounts for, and extends, previous theoretical studies on the subject; b) it delivers a rationale for the ES lifetimes observed in retinal proteins, both archeal and visual rhodopsins, as well as in solvent; and c) the transferability of the discovered trends on PSB mimics is demonstrated.
authors: Dipartimento di Chimica "G. Ciamician″, Universita' degli Studi di Bologna , Via Selmi, 2 I - 40126 Bologna, Italy.|Chemistry Department, Faculty of Science, Damanhour University , Damanhour 22511, Egypt.
authors: Mohsen M T
authors: MM
authors: El-Tahawy
authors: Dipartimento di Chimica "G. Ciamician″, Universita' degli Studi di Bologna , Via Selmi, 2 I - 40126 Bologna, Italy.
authors: Artur
authors: A
authors: Nenov
authors: Dipartimento di Chimica "G. Ciamician″, Universita' degli Studi di Bologna , Via Selmi, 2 I - 40126 Bologna, Italy.|Université de Lyon, Université Claude Bernard Lyon 1, ENS Lyon, Centre Nationale de Recherche Scientifique, 46 allée d'Italie, 69007 Lyon Cedex 07, France.
authors: Marco
authors: M
authors: Garavelli
mesh_terms: D004560:Electricity; D007536:Isomerism; D008968:Molecular Conformation; D011522:Protons; D011789:Quantum Theory; D012172:Retinaldehyde / Q000737:chemistry*; D012545:Schiff Bases / Q000737:chemistry*; D014466:Ultraviolet Rays
chemical_list: D011522:Protons; D012545:Schiff Bases; D012172:Retinaldehyde