title: Inelastic electron interaction with chloroform clusters embedded in helium droplets.
abstract: The inelastic electron interaction (ionization/attachment) with chloroform embedded in helium droplets has been studied utilizing a two-sector field mass spectrometer. Positive mass spectra have been recorded at the electron energy of 70 eV and are compared with previous results in the gas phase and with other systems embedded in helium droplets. Moreover, the negative ion mass spectrum has been recorded at the electron energy of 1.5 eV. Both negative and positive mass spectra show that chloroform clusters are easily formed by embedding single molecules in the helium droplets. Moreover, for anions appearing in the mass spectrum, the ion yield has been determined as function of the electron energy. While no parent anion of chloroform can be observed in the gas phase, the present cluster environment allows the stabilization of the transient negative ion. The influence of the helium droplet upon the ionization or attachment process of the embedded chloroform is discussed.
authors.affiliation: Institut für Ionenphysik and Angewandte Physik and Center for Molecular Biosciences Innsbruck, Leopold-Franzens Universität Innsbruck, Technikerstrasse 25, A-6020 Innsbruck, Austria.
authors.forename: Stephan
authors.initials: S
authors.lastname: Denifl
authors.forename: Fabio
authors.initials: F
authors.lastname: Zappa
authors.forename: Ingo
authors.initials: I
authors.lastname: Mähr
authors.forename: Andreas
authors.initials: A
authors.lastname: Mauracher
authors.forename: Michael
authors.initials: M
authors.lastname: Probst
authors.forename: Tilmann D
authors.initials: TD
authors.lastname: Märk
authors.forename: Paul
authors.initials: P
authors.lastname: Scheier
mesh_terms: D002725:Chloroform / Q000737:chemistry*; D004548:Elasticity; D004583:Electrons; D006371:Helium / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry; D007477:Ions / Q000737:chemistry; D013058:Mass Spectrometry; D013696:Temperature
chemical_list: D007477:Ions; D006371:Helium; D002725:Chloroform; D006859:Hydrogen