Spectral extension of two glycolic acid conformers into the submillimeter regime

The rotational spectrum of glycolic acid has been extended to frequencies from 318 to 1000 GHz. Analysis of this spectrum builds upon previous experimental and theoretical studies performed on glycolic acid conformers. Extensive new assignments were made for the ground vibrational state of the SSC conformer of glycolic acid in addition to the two lowest vibrational states. Assignments were also expanded for the AAT conformer of glycolic acid. This work improves the precision of some rotational constants and nearly all of the centrifugal distortion constants for each conformer and vibrational state. The spectral predictions based on these refined parameters will facilitate the search for glycolic acid in the interstellar medium at frequencies covered by submillimeter observatories. [Display omitted] •The rotational spectrum of glycolic acid has been extended from 318 to 1000 GHz.•Analysis of this spectrum builds upon previous experimental and theoretical studies.•Assignments were made for the SSC and AAT conformers.•Precision of the rotational and centrifugal distortion constants was improved.•New spectral predictions will facilitate observational searches for glycolic acid.