The H-bond interaction between glycine and H2O has been studied by a combined theoretical (DFT(B3LYP)/6-31++G(**)) and experimental (matrix-isolation FT-IR) methodology. The 1:1 and 1:2 complexes of the most stable conformation (I) of glycine appear to be neutral complexes which have been vibrationally characterized in detail. The higher stoichiometry complexes (glycine).(H2O)n with n larger than 3 are demonstrated to be zwitterionic H-bonded complexes. A set of characteristic IR absorption bands for this zwitterionic structure has been observed in low-temperature Ar matrices. This would be the first experimental IR evidence for proton transfer occurring between the NH2 and COOH groups of amino acids by a H-bonded water molecular channel in isolated conditions.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.