Raman and infrared spectra of solid glyoxal‐d1 and glyoxal‐d2

Abstract

AbstractThe Raman spectra of solid glyoxal‐d1 and glyoxal‐d2 have been recorded at −190°C from 100 to 3000 cm−1. Fundamental frequencies of glyoxal‐d2 were observed at 2169, 1709, 1131, 944, 908 and 543 cm−1 and assigned as the CD stretching, CO stretching, CD rocking, CC stretching, CD wagging and CCO bending modes respectively. The infrared spectra of the solids have been recorded from 90 to 4000 cm−1. For C2D2O2 this gives the other six fundamentals at 2177, 1685, 1022, 643, 343 and 174 cm−1. The rule of mutual exclusion holds rigorously showing that the molecule has a centrosymmetric structure in the crystal and that the site is Ci (1). The Raman and infrared spectra of glyoxal‐d1 show many coincidences, confirming the breakdown of the rule of mutual exclusion when the center of symmetry is lost on partial deuteration. Fundamentals are assigned at 2882, 2161, 1720, 1699, 1352, 1116, 1005, 981, 710, 548, 357 and 193 cm−1. The frequency shifts upon solidification are discussed.