Characterization of new FIR laser lines from CD/sub 3/-rocking and asymmetric CD/sub 3/ deformation modes of /sup 13/CD/sub 3/OD

Sub-Doppler Infrared Spectra of the OH–Stretch Fundamental of 13C-Methanol

“…Pieces of filter paper were partially submerged in a methanol reservoir to increase its evaporation rate. The resulting partial pressure of 13 C-methanol was close to that of its saturated vapor with liquid volumes in the range of 1-5 ml. A cold trap was placed between the diffusion pumps and the backing pump to recover part of the 13 Cmethanol used in the experiment.…”

“…The resulting partial pressure of 13 C-methanol was close to that of its saturated vapor with liquid volumes in the range of 1-5 ml. A cold trap was placed between the diffusion pumps and the backing pump to recover part of the 13 Cmethanol used in the experiment. The purity of the 13 C-methanol recovered from the cold trap was estimated from proton NMR spectra to be ϳ95%, the rest being mostly water.…”

“…The vacuum chamber was evacuated to ϳ6 ϫ 10 Ϫ6 Torr by two Varian diffusion pumps (VHS-4 and VHS-6). A mixture of 13 C-methanol (Cambridge Isotope Laboratories, 99%) and argon (Parry Corporation, 99.995%) was produced by bubbling argon through liquid 13 C-methanol at 0°C. The gas mixture was expanded through a pulsed slit nozzle (23) at 90 -100 kPa stagnation pressure.…”

“…A cold trap was placed between the diffusion pumps and the backing pump to recover part of the 13 Cmethanol used in the experiment. The purity of the 13 C-methanol recovered from the cold trap was estimated from proton NMR spectra to be ϳ95%, the rest being mostly water. Of the 10 g of isotopic material used during about 80 h of run time, about 8 g were recovered.…”

“…Sixty-four of the 86 obtained origins were fitted by means of the Lees and Baker Hamiltonian (21), producing a value of 410 cm Ϫ1 for the excited state torsional barrier. In the present study, rotational assignments in the OH stretch fundamental of 13 C-methanol are reported and fitted to a global Hamiltonian to obtain an estimate of the torsional barrier. In subsequent work (22), these assignments were used for stateselection in double-resonance IRLAPS experiments on 13 Cmethanol.…”