A new monohydrated molecular salt of GABA with l-tartaric acid: the structure-forming role of water

Abstract

A new hydrated molecular salt of GABA was crystallized, and its crystal structure was solved. This is the first example of a hydrated molecular salt of an achiral amino acid with L-tartaric acid and also the first communication on a hydrated molecular salt of GABA with a chiral molecule. The structure contains molecular bi-layers of L-tartaric acid anions connected together by R⁴₄(12) motifs based on GABA cations and water molecules. The role of water in the 3D hydrogen bonded network was analyzed. Structural similarity between the monohydrates of GABA with L-tartaric and orotic acid was found. We can suppose that the general R⁴₄(12) motif including 2 GABA cations and 2 water molecules would be common for other hydrated molecular salts of GABA with other co-formers, which will be obtained in the future. The stability on storage, thermal behavior and dehydration process for the novel molecular compound were investigated.