Vibrational spectra of glyoxylic acid monomers

Infrared spectra of glyoxylic acid monomers, including the hydroxyl deuterated and general O-18 isotopomers, are reported for argon and nitrogen matrix-isolated samples in the range 400–4000 cm^?1. Values for all 15 fundamental vibrations of the intramolecular H-bonded monomer are listed. Bands attributed to the trans-carbonyl conformer with a free car?yl group are also observed and about half of its fundamental frequencies are listed. Some modes of the intramolecular H-bonded glyoxylic acid monomer are strongly matrix dependent, and differences between Ar and N₂ matrix spectra are exploited in sorting out the spectral information.