title: Effect of the symmetry of H2 molecules on their rotations around an OCS molecule in superfluid 4He droplets.
abstract: The infrared spectra of OCS-(H2)(n) clusters in cold (0.15 K) superfluid 4He droplets coated with 3He exhibit resolved rotational bands for each n up to n=8 para-H2 (pH(2)) or ortho-D2 (oD(2)) molecules. An analysis of the different Q-branch intensities based on the different spin symmetries of pH(2) and oD(2) indicates the formation of symmetric 5- or 6-membered rings around the linear carbonyl sulfide (OCS) chromophore. The rings of distinguishable oD(2) are found to undergo axial rotations, whereas for 6 pH(2) molecules the symmetry-allowed rotational levels lie too high to be excited at the 0.15 K droplet temperatures.
authors.affiliation: Max-Planck-Institut für Strömungsforschung, Bunsenstrasse 10, D-37073 Göttingen, Germany.
authors.forename: Slava
authors.initials: S
authors.lastname: Grebenev
authors.forename: Boris
authors.initials: B
authors.lastname: Sartakov
authors.forename: J Peter
authors.initials: JP
authors.lastname: Toennies
authors.forename: Andrej
authors.initials: A
authors.lastname: Vilesov