p-Benzoquinone in aqueous solution: stark shifts in spectra, asymmetry in solvent structure
2007 (English)In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 9, 470-480 p.Article in journal (Refereed) Published
Results from a simulation of p-benzoquinone (PBQ) in water is presented. An explicit solvent representation is used together with a multiconfigurational ab initio quantum chemical method. The electronic n -> pi* transitions are studied in aqueous solution and the two such transitions are both blue-shifted but to different degree. Both non-equilibrium and many-body effects are found to have decisive influence on the solvation: despite stronger hydrogen bonding between solute and solvent in an excited state than in the ground state, there is a blue-shift, and the solvent structure around the non-polar PBQ is asymmetric, which is argued to come from special many-body effects. The unusual result of strengthened hydrogen bonds in the excited state that follows from an excitation of a non-bonding electron on a proton acceptor, is explained by the near-linear Stark shift that is present in the transition.
Place, publisher, year, edition, pages
2007. Vol. 9, 470-480 p.
IdentifiersURN: urn:nbn:se:uu:diva-145689DOI: 10.1039/b613833kOAI: oai:DiVA.org:uu-145689DiVA: diva2:396624