title: Absorption spectroscopy of adenine, 9-methyladenine, and 2-aminopurine in helium nanodroplets.
abstract: High-resolution absorption spectra of adenine, 9-methyladenine and 2-aminopurine in helium nanodroplets have been recorded. In contrast to molecular beam experiments, large variations in linewidths are observed for adenine and 9-methyladenine. At the same time, the spectrum of 2-aminopurine remains sharp upon solvation in helium droplets. The line broadening observed for adenine and 9-methyladenine is attributed to a significant decrease of the lifetime of the (1)L(b)(ππ*) state and of (1)nπ* levels vibronically coupled to this state. The origin of the lifetime reduction is argued to be related to the increased accessibility of the (1)nπ*/(1)L(b)(ππ*) conical intersection upon solvation of these molecules in liquid helium.
authors.affiliation: Van 't Hoff Institute for Molecular Sciences, Faculty of Science, University of Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam, The Netherlands.
authors.forename: Szymon
authors.initials: S
authors.lastname: Smolarek
authors.forename: Anouk M
authors.initials: AM
authors.lastname: Rijs
authors.forename: Wybren Jan
authors.initials: WJ
authors.lastname: Buma
authors.forename: Marcel
authors.initials: M
authors.lastname: Drabbels
mesh_terms: D015075:2-Aminopurine / Q000737:chemistry* / Q000528:radiation effects; D000042:Absorption; D000225:Adenine / Q000031:analogs & derivatives* / Q000737:chemistry* / Q000528:radiation effects; D055598:Chemical Phenomena; D006371:Helium / Q000737:chemistry*; D015394:Molecular Structure; D012997:Solvents / Q000737:chemistry; D013057:Spectrum Analysis / Q000379:methods*
chemical_list: D012997:Solvents; D006371:Helium; D015075:2-Aminopurine; C013115:9-methyladenine; D000225:Adenine