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dc.contributor.authorMohammed, Omar F.
dc.contributor.authorXiao, Dequan
dc.contributor.authorBatista, Victor S.
dc.contributor.authorNibbering, Erik Theodorus Johannes
dc.date.accessioned2015-08-03T11:53:54Z
dc.date.available2015-08-03T11:53:54Z
dc.date.issued2014-04-17
dc.identifier.issn10895639
dc.identifier.pmid24684387
dc.identifier.doi10.1021/jp501612f
dc.identifier.urihttp://hdl.handle.net/10754/563536
dc.description.abstractWe combine ultrafast electronic and vibrational spectroscopy and computational modeling to investigate the photoinduced excited-state intramolecular hydrogen-transfer dynamics in 1,8-dihydroxy-9,10-anthraquinone (DHAQ) in tetrachloroethene, acetonitrile, dimethyl sulfoxide, and methanol. We analyze the electronic excited states of DHAQ with various possible hydrogen-bonding schemes and provide a general description of the electronic excited-state dynamics based on a systematic analysis of femtosecond UV/vis and UV/IR pump-probe spectroscopic data. Upon photoabsorption at 400 nm, the S 2 electronic excited state is initially populated, followed by a rapid equilibration within 150 fs through population transfer to the S 1 state where DHAQ exhibits ESIHT dynamics. In this equilibration process, the excited-state population is distributed between the 9,10-quinone (S2) and 1,10-quinone (S1) states while undergoing vibrational energy redistribution, vibrational cooling, and solvation dynamics on the 0.1-50 ps time scale. Transient UV/vis pump-probe data in methanol also suggest additional relaxation dynamics on the subnanosecond time scale, which we tentatively ascribe to hydrogen bond dynamics of DHAQ with the protic solvent, affecting the equilibrium population dynamics within the S2 and S1 electronic excited states. Ultimately, the two excited singlet states decay with a solvent-dependent time constant ranging from 139 to 210 ps. The concomitant electronic ground-state recovery is, however, only partial because a large fraction of the population relaxes to the first triplet state. From the similarity of the time scales involved, we conjecture that the solvent plays a crucial role in breaking the intramolecular hydrogen bond of DHAQ during the S2/S1 relaxation to either the ground or triplet state. © 2014 American Chemical Society.
dc.description.sponsorshipV.S.B. acknowledges financial support by the National Science Foundation (Grant CHE 0911520) and supercomputer time from NERSC and from the High Performance Computing facilities at Yale University. We thank Dr. Alexey Gusev for allowing access to his facilities at Ultrafast Systems LLC, 1748 Independence Blvd. Bld. G, Sarasota, FL 34234, U.S.A. We also thank Dr. Allen Ricks for his help and support during conducting the time-resolved data.
dc.publisherAmerican Chemical Society (ACS)
dc.titleExcited-state intramolecular hydrogen transfer (ESIHT) of 1,8-Dihydroxy-9,10-anthraquinone (DHAQ) characterized by ultrafast electronic and vibrational spectroscopy and computational modeling
dc.typeArticle
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Division
dc.contributor.departmentChemical Science Program
dc.contributor.departmentKAUST Solar Center (KSC)
dc.identifier.journalThe Journal of Physical Chemistry A
dc.contributor.institutionDepartment of Chemistry and Chemical Engineering, University of New Haven, 300 Boston Post Road, West Haven, CT 06516, United States
dc.contributor.institutionDepartment of Chemistry, Yale University, P.O. Box 208107, New Haven, CT 06520, United States
dc.contributor.institutionMax Born Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max Born Strasse 2A, D-12489 Berlin, Germany
kaust.personMohammed, Omar F.
dc.date.published-online2014-04-17
dc.date.published-print2014-05


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