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Impact of water on the cis-trans photoisomerization of hydroxychalcones.

hal.structure.identifierUniversidade Nova de Lisboa = NOVA University Lisbon [NOVA]
dc.contributor.authorLEYDET, Yoann
hal.structure.identifierInstitut des Sciences Moléculaires [ISM]
hal.structure.identifierLaboratoire Ondes et Matière d'Aquitaine [LOMA]
dc.contributor.authorBATAT, Pinar
hal.structure.identifierLaboratoire Ondes et Matière d'Aquitaine [LOMA]
dc.contributor.authorJONUSAUSKAS, Gediminas
hal.structure.identifierInstitut des Sciences Moléculaires [ISM]
hal.structure.identifierLaboratoire Ondes et Matière d'Aquitaine [LOMA]
dc.contributor.authorDENISOV, Sergey A.
hal.structure.identifierUniversidade Nova de Lisboa = NOVA University Lisbon [NOVA]
dc.contributor.authorLIMA, João Carlos
hal.structure.identifierUniversidade Nova de Lisboa = NOVA University Lisbon [NOVA]
dc.contributor.authorPAROLA, A. Jorge
hal.structure.identifierInstitut des Sciences Moléculaires [ISM]
dc.contributor.authorMCCLENAGHAN, Nathan D.
hal.structure.identifierUniversidade Nova de Lisboa = NOVA University Lisbon [NOVA]
dc.contributor.authorPINA, Fernando
dc.date.created2013-03-20
dc.date.issued2013
dc.identifier.issn1089-5639
dc.description.abstractEnThe photochromism of a 2-hydroxychalcone has been studied in CH3CN and H2O/CH3OH (1/1, v/v), as well as in analogous deuterated solvents using steady-state (UV-vis absorption, (1)H and (13)C NMR) and time-resolved (ultrafast transient absorption and nanosecond flow flash photolysis) spectroscopies. Whereas the irradiation of trans-chalcone (Ct) under neutral pH conditions leads to the formation of the same final chromene derivative (B) in both media, two distinct photochemical mechanisms are proposed in agreement with thermodynamic and kinetic properties of the chemical reaction network at the ground state. Following light excitation, the first steps are identical in acetonitrile and aqueous solution: the Franck-Condon excited state rapidly populates the trans-chalcone singlet excited state (1)Ct* (LE), which evolves into a twisted state (1)P*. This excited state is directly responsible for the photochemistry in acetonitrile in the nanosecond time scale (16 ns) leading to the formation of cis-chalcone (Cc) through a simple isomerization process. The resulting cis-chalcone evolves into the chromene B through a tautomerization process in the ground state (τ = 10 ms). Unlike in acetonitrile, in H2O/CH3OH (1/1, v/v), the P* state becomes unstable and evolves into a new state attributed to the tautomer (1)Q*. This state directly evolves into B in one photochemical step through a consecutive ultrafast tautomerization process followed by electrocyclization. This last case represents a new hypothesis in the photochromism of 2-hydroxychalcone derivatives.
dc.language.isoen
dc.publisherAmerican Chemical Society
dc.rights.urihttp://creativecommons.org/licenses/by-nc-sa/
dc.title.enImpact of water on the cis-trans photoisomerization of hydroxychalcones.
dc.typeArticle de revue
dc.identifier.doi10.1021/jp402761j
dc.subject.halPhysique [physics]/Physique [physics]/Chimie-Physique [physics.chem-ph]
dc.subject.halChimie/Chimie théorique et/ou physique
bordeaux.journalJournal of Physical Chemistry A
bordeaux.page4167-4173
bordeaux.volume117
bordeaux.issue20
bordeaux.peerReviewedoui
hal.identifierhal-00845493
hal.version1
hal.popularnon
hal.audienceInternationale
hal.origin.linkhttps://hal.archives-ouvertes.fr//hal-00845493v1
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