ANALYSIS OF FORMALDEHYDE IN THE 3.5 MICRON REGION

$^{1}$C. Secroun, A. Barbe, and P, Jouve, J. Mol. Spectrose. 45, 1 (1973). $^{2}$ S. J. Yao, Ph.D. dissertation, University of Minnesota, 1966; S. J. Yao and J. Overend, Spectrochem. Acta, in press. $^{3}$ J. Overend J. Chem. Phys., in press. $^{4}$ R. A. McClatchey, W. S. Benedict, S. A. Clough, D. E. Burch, R. F. Calfee, K. Fox, L. S. Rothman, and J. S. Garing, """"AFCRL Atmospheric Absorption Line Parameters Compilation,"""" Appl. Opt. 12 2545 (1973). Support extended this research by NSF Grant No. MPS-7421471 is gratefully acknowledged.Author Institution: Florida State University; Jet Propulsion LaboratoryThe formaldehyde spectrum was recorded at $0.022 cm^{-1}$ resolution with the Florida State University grating spectrometer. Approximately 5000 transitions were measured in the region from 2630 to $3030 cm^{-1}$. Lines have been assigned to the fundamental bands, $\nu_{1}$ and $\nu_{5}$ for J $\leq$ 25 and K $\leq$ 9. In addition, partial assignments have been made to the three combination bands, $\nu_{3} + \nu_{6} , \nu_{2} + \nu_{4}$ and $\nu_{2} + \nu_{6}$. To obtain molecular parameters, energy levels have been calculated through the diagonalization of the rigid asymmetric rotor with the Kivelson-Wilson terms evaluated for distortion effects. A non-linear least squares fit of combination differences between levels with J $\leq$ 24 and K $\leq$ 9 has determined ground state constants. In addition, upper state energy levels of the more thoroughly assigned bands have been fit to obtain upper state inertial parameters