Internal rotation and spin conversion of CH3OH in solid para-hydrogen.
The quantum solid para-hydrogen (p-H2) has recently proven useful in matrix isolation spectroscopy. Spectral lines of compounds embedded in this host are unusually narrow, and several species have been reported to rotate in p-H2. We found that a p-H2 matrix inhibits rotation of isolated methanol (CH3OH) but still allows internal rotation about the C-O bond, with splittings of the E/A torsional doublet in internal rotation-coupled vibrational modes that are qualitatively consistent with those for CH3OH in the gaseous phase. This simplified high-resolution spectrum further revealed the slow conversion of nuclear spin symmetry from species E to species A in the host matrix, offering potential insight into nuclear spin conversion in astrophysical sources.
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
Lees
R M
RM
Xu
Li-Hong
LH
Hougen
Jon T
JT