Citation:
Abstract:
A reanalysis of the n3 , n4 , and n6 interacting bands of D2CO has been carried out in the region 850–1250 cm01 using high-resolution Fourier transform spectra recorded at Giessen. As compared to the previous study of these bands (1987, K. Nakagawa, R. H. Schwendeman, and J. W. C. Johns, J. Mol. Spectrosc. 122, 462–476) higher J and Ka transitions were assigned for the three bands, leading to a better determination of the upper state constants. The £3 1, £4 1, and £6 1 experimental energy levels were introduced in a least-squares fit calculation together with the microwavemeasurements available in the literature in order to obtain the upper state parameters (band centers, rotational and coupling constants) . In this calculation, which allowed us to reproduce both the infrared and the microwave measurements to within their experimental accuracies, the A-, B-, and C-type Coriolis interactions involving the rotational levels belonging to the £4 1 and £6 1, £3 1 and £4 1, and £3 1 and £6 1 interacting states respectively were explicitly taken into account. Finally, from the intensities, a new determination of the relative values of the q3 , q4 , andq6 first derivatives of the D2CO dipole moment was performed. q 1998 Academic Press