The magnetic rotation spectrum of glyoxal

Abstract

Twenty-one bands of the first triplet–singlet system of glyoxal (³A_u–¹A_g) have been photographed in absorption and in magnetic rotation using high resolving power. Analysis yields the following vibrational frequencies for the molecule in the ³A_u state: v₂ = 1458_∙9 cm⁻¹, v₄ = 963_∙4 cm⁻¹,v₅ = 502_∙6 cm⁻¹, v₇ = 234_∙3 cm⁻¹, and v₁₂ = 391_∙9 cm⁻¹. These frequencies are very similar to those for glyoxal in the corresponding ¹A_u excited state.