The 4550 Å band system of glyoxal. II. Vibration–rotational analyses for 12 bands of C₂H₂O₂

Abstract

Rotational analyses have been performed for 12 bands of the 1 A u – 1 A g (π*–n) transition of glyoxal. Approximately 15 000 lines have been assigned, and rotational and vibrational constants obtained by computer methods. The vibrations investigated are ν 2 ′ (CO stretching), ν 4 ′ (C–C stretching), ν 5 ′ and ν 5 ″ (CCO bending), and the torsional levels with ν 7 ′ = 1–4 and ν 7 ″ = 1–3. A Coriolis interaction has been found involving the vibrations ν 7 (a u ) and ν 12 (b u ). Some weak anharmonic interactions have also been identified.