title: High resolution quantum cascade laser studies of the ν3 band of methyl fluoride in solid para-hydrogen.
abstract: Spectra of solid para-H(2) doped with CH(3)F at 1.8 K are studied in the ν(3) region (~1040 cm(-1)) using a quantum cascade laser source. As shown previously, residual ortho-H(2) in the sample (~1000 ppm) gives rise to distinct spectral features due to clusters of the form CH(3)F-(ortho-H(2))(N), with N = 0, 1, 2, 3, etc. Brief annealing at 7 K is found to give narrower spectral lines (≥0.006 cm(-1)) than conventional (5 K) annealing, and causes the N = 3 and 4 lines to fragment into two or more components. The N = 3 line is observed to be particularly stable and persistent. The N = 0 line (no ortho-H(2) neighbors) is resolved into two closely spaced (≈0.007 cm(-1)) components which are assigned to the K = 0 and 1 states of CH(3)F rotating around its C(3v) symmetry axis (ortho- and para-CH(3)F, respectively). Similar K-structure is also evident for other lines. Weak but persistent features ("N = 1/2 lines") are observed mid way between N = 0 and 1.
authors.affiliation: Department of Physics, Tokyo Institute of Technology, Ohokayama 2-12-1, Tokyo 152-8551, Japan. robert.mckellar@nrc-cnrc.gc.ca
authors.forename: A R W
authors.initials: AR
authors.lastname: McKellar
authors.forename: Asao
authors.initials: A
authors.lastname: Mizoguchi
authors.forename: Hideto
authors.initials: H
authors.lastname: Kanamori
mesh_terms: D006845:Hydrocarbons, Fluorinated / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry*; D007834:Lasers; D011789:Quantum Theory
chemical_list: D006845:Hydrocarbons, Fluorinated; C029999:fluoromethane; D006859:Hydrogen