title: Bicycle-pedal isomerization in a rhodopsin chromophore model.
abstract: Probing the isomerization of a retinal chromophore model we have found the first ab initio realization of the so-called "bicycle-pedal mechanism". In an ensemble of 47 starting geometries generated by ground-state zero-point-energy sampling one single trajectory followed the aforementioned reaction mode which was proposed by Warshel in 1976. Furthermore restrained optimization of synchronous rotation mode shows that two-double-bond isomerization is barrierless for the conrotatory and disrotatory pathway.
authors.affiliation: Department of Chemistry, University of Duisburg-Essen, 45141 Essen, Germany.
authors.forename: Igor
authors.initials: I
authors.lastname: Schapiro
authors.forename: Oliver
authors.initials: O
authors.lastname: Weingart
authors.forename: Volker
authors.initials: V
authors.lastname: Buss
mesh_terms: D003198:Computer Simulation; D007536:Isomerism; D008958:Models, Molecular; D011090:Polyenes / Q000737:chemistry*; D012172:Retinaldehyde / Q000737:chemistry; D012545:Schiff Bases / Q000737:chemistry; D025603:Sensory Rhodopsins / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D011090:Polyenes; D012545:Schiff Bases; D025603:Sensory Rhodopsins; D012172:Retinaldehyde