Hydrogen-bonded complexes of glycolic acid with one and two water molecules

Ab initio calculations are used to locate 12 and 17 local minima on the potential energy surfaces of the CH2OHCOOH–H2O and CH2OHCOOH–H2O–H2O complexes, respectively. In the lowest-energy structure of CH2OHCOOH–H2O, the water forms two H-bonds with the carboxylic group of the glycolic acid. The lowest-energy structure of CH2OHCOOH–H2O–H2O consists of a trans water dimer attached to the carboxylic group by two H-bonds. The intramolecular H-bond remains intact in the glycolic acid moiety of the lowest-energy structures of both complexes.