Direct spectral evidence of single-axis rotation and ortho-hydrogen-assisted nuclear spin conversion of CH3F in solid para-hydrogen.
Observation of two weak absorption lines from the E (K = 1) level and one intense feature from A (K = 0) for degenerate modes nu(4) and nu(6) of CH(3)F provides direct spectral evidence that CH(3)F isolated in p-H(2) rotates about only its symmetry axis, and not about the other two axes. An interaction between A and E vibrational levels caused by the partially hindered spinning rotation is proposed. Conversion of nuclear spin between A and E components of CH(3)F is rapid when p-H(2) contains some o-H(2), but becomes slow when the proportion of o-H(2) is much decreased.
Lee
Yuan-Pern
YP
Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, 1001, Ta-Hsueh Road, Hsinchu 30010, Taiwan. yplee@mail.nctu.edu.tw
Wu
Yu-Jong
YJ
Hougen
Jon T
JT