A high-resolution FT-IR study of the fundamental bands nu(6), nu(10), and nu(11) of trans-glyoxal

The high-resolution Fourier transform infrared spectrum of trans-glyoxal in the gas phase has been recorded in the spectral regions 700-900 cm(-1), 1200-1400 cm(-1), and 1600-1800 cm(-1) with a resolution ranging from 0.0020 to 0.0025 cm(-1). The spectrum displays extensive rotational structures which are assigned to the three fundamental bands upsilon(6) (A(u), 801.5 cm(-1)), upsilon(10) (B-u, 1732.1 cm(-1)), and upsilon(11) (B-u, 1312.5 cm(-1)). A total of ca. 5000 absorption lines have been assigned to these three bands. A simultaneous ground state combination difference analysis of all three bands yields improved ground state spectroscopic constants for trans-glyoxal. Furthermore, a number of spectroscopic constants for the nu(6) and nu(11) levels have been determined for the first time