15min:

MARIO E. FAJARDO, AFRL/MNME, Energetic Materials Branch, Ordnance Division, U.S. Air Force Research Lab, 2306 Perimeter Rd., Eglin AFB, FL 32542-5910. mario.fajardo@eglin.af.mil; TAKAMASA MOMOSE, Division of Chemistry, Graduate School of Science, Kyoto University, Kyoto, 605-8502, Japan.

We report our analysis of high-resolution rovibrational infrared absorption spectra of carbon monoxide (CO) molecules isolated in solid parahydrogen (pH₂). Experimental data, comprising roughly a dozen transitions for each isotopomer, are presented for ¹²C¹⁶O, ¹³C¹⁶O, ¹²C¹⁸O, and ¹³C¹⁸O. Assignments are made using a Hamiltonian derived using crystal field theory for a diatomic rotor in a D_3h symmetry single-substitutional trapping site in hexagonal-close-packed solid pH₂. Successful fitting of these spectra requires treating the CO rotational constants (B_e, D_e, _e) as adjustable parameters; the resulting B_e(pH₂) values are reduced to roughly 80% of their gas phase values.