Microwave spectrum of salicylic acid

The rotational spectra of salicylic acid and of three OD deuterated species have been investigated by free jet millimiter-wave absorption spectroscopy. Only lines of the most stable conformer, the one with an intramolecular hydrogen bond between the phenolic hydrogen and the carbonyl oxygen, have been observed. The positions of the phenolic and carboxylic hydrogens have been precisely derived.