The pure rotational spectrum of glycolaldehyde isotopologues observed in natural abundance

The pure rotational spectrum of glycolaldehyde has been recorded from 6.5-20 GHz and 25-40 GHz in two pulsed-jet chirped pulse Fourier transform microwave spectrometers. The high phase stability of the spectrometers enables deep signal integration, allowing transitions from the ¹³C-substituted, ¹⁸O-substituted, and deuterium-substituted isotopologues to be observed in natural abundance. Transitions from HCOCH₂¹⁸OH are reported for the first time. Additional transitions from the ¹³C-substituted, deuterium-substituted, and HC¹⁸OCH₂OH isotopologues, as well as previously unobserved weak lines from the main isotopologue, have been observed. Transitions from all isotopologues are used with previously reported transitions to refine the spectroscopic parameters for each isotopologue. A Kraitchman analysis was performed using the experimental rotational constants to determine the molecular structure of glycolaldehyde.