High resolution quantum cascade laser studies of the nu(3) band of methyl fluoride in solid para-hydrogen

作者：McKellar A R W^*; Mizoguchi Asao; Kanamori Hideto

来源：Journal of Chemical Physics, 2011, 135(12): 124511.

DOI：10.1063/1.3640888

Spectra of solid para-H-2 doped with CH3F at 1.8 K are studied in the nu(3) region (similar to 1040 cm(-1)) using a quantum cascade laser source. As shown previously, residual ortho-H-2 in the sample (similar to 1000 ppm) gives rise to distinct spectral features due to clusters of the form CH3F-(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 (approximate to 0.007 cm(-1)) components which are assigned to the K = 0 and 1 states of CH3F rotating around its C3v symmetry axis (ortho- and para-CH3F, 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.

• 出版日期2011-9-28