High-resolution study of the u9 fundamental band of trans-glyoxal

The spectrum of trans-glyoxal has been recorded at a resolution of about 0.004 cm-1 in the region from 2770 to 2900 cm-1. 1549 lines have been assigned to the type B band due to the u9 (bu) fundamental (antisymmetric C-H stretching vibration). The groundstate rotational constants confirm earlier values and new constants are determined for the excited state of u9.