Experimental and theoretical investigation of hydrogen bonded complexes between glycolic acid and water

Theoretical MP2 and B3LYPD3 calculations, as well as experimental matrix isolation infrared spectroscopy studies, were used to investigate the 1:1 complexes formed between glycolic acid and water. Out of five computationally predicted forms of GA⋯H₂O complex the most stable one was detected experimentally in solid argon. This structure is characterized by two intermolecular OH⋯O hydrogen bonds depicting a six-member ring in which water acts both as a proton acceptor and as a proton donor. Two other structures with the alcoholic OH group acting as a proton donor are also tentatively suggested to be present in solid argon.