ABSOLUTE INFRARED INTENSITIES IN THE FUNDAMENTALS NU(1) AND NU(3) OF ARSINE

FT Spectra were recorded with a resolution of 0.006 cm-1 (apodized FWHM), to determine intensity parameters relative to the fundamentals ν1 and ν3 of AsH3. The resolution now available allowed us to improve the line position analysis over that in previous work by Olson et al. A dyad system was used to account for the strong Coriolis coupling between ν1 and ν3 induces, through a large element in Δ (K - l3) = ±3, many perturbation-allowed transitions. Absolute intensities were measured for 387 lines corresponding to 494 transitions of ν1 and ν3. Only 343 of these were retained for the intensity fit because of blendings. Band strengths of ν1 and ν3 were estimated as 265.8 (8.6) and 737.5 (9.5) cm-2 atm-1 at 296 K, respectively. The energy and intensity parameters thus derived were used to produce a new prediction of line positions and intensities, much more reliable than those previously available, for further planetary applications. © 1993 Academic Press, Inc.