Doped rare gas clusters up to completion of first solvation shell, CO2-(Rg)n, n = 3-17, Rg = Ar, Kr, Xe

Abstract

Spectra of rare gas atom clusters containing a single carbon dioxide molecule are observed using a tunable mid-infrared (4.3 micron) source to probe a pulsed slit jet supersonic expansion. There are relatively few previous detailed experimental results on such clusters. The assigned clusters include CO2-Arn with n = 3, 4, 6, 9, 10, 11, 12, 15, and 17, as well as CO2-Krn and -Xen with n = 3, 4, and 5. Each spectrum has (at least) partially resolved rotational structure, and each yields precise values for the shift of the CO2 vibrational frequency (nu3) induced by the nearby rare gas atoms, together with one or more rotational constants. These results are compared with theoretical predictions. The more readily assigned CO2-Arn species tend to be those with symmetric structures, and CO2-Ar17 represents completion of a highly symmetric (D5h) solvation shell. Those not assigned (e.g. n = 7, 13) are probably also present in the observed spectra, but with band structures which are not well-resolved and thus not recognizable. The spectra of CO2-Ar9, -Ar15, and -Ar17 suggest the presence of sequences involving very low frequency (~2 cm-1) cluster vibrational modes, an interpretation which should be amenable to theoretical confirmation (or rejection).

34 pages, 12 figures, 9 tables

References in corpus (4)

• Symmetry breaking of the bending mode of CO2 in the presence of Ar
• New infrared spectra of CO2-Xe: modeling Xe isotope effects, intermolecular bend and stretch, and symmetry breaking of the CO2 bend
• Infrared spectra of (CO${}_2$)${}_2$-Rg trimers, Rg = Ne, Ar, Kr, and Xe
• Spectra of CO2-Rg2 and CO2-Rg-He trimers (Rg = Ne, Ar, Kr, and Xe): intermolecular CO2 rock, vibrational shifts and three-body effects