title: DL-3-aminoisobutyric acid monohydrate.
abstract: The title acid, 3-amino-2-methylpropanoic acid monohydrate, C4H9NO2.H2O, crystallized in the centrosymmetric space group Pbca in the zwitterionic form. The three H atoms on N, which are involved in hydrogen bonding, are ordered. The three intermolecular N-H...O hydrogen bonds have N...O distances ranging from 2.758 (2) to 2.809 (2) A and N-H...O angles ranging from 149 (2) to 171 (1) degrees. The two intermolecular O-H...O hydrogen bonds have O...O distances 2.739 (2) and 2.755 (2) A, and O-H...O angles 170 (2) and 175 (2) degrees. Each acid molecule and its associated water molecule are directly hydrogen bonded to five acid molecules and two water molecules; the structure comprises two subsets of molecules which are not cross-linked by these hydrogen bonds. Through basic second-level graphs, approximately two-thirds of the hydrogen-bonding patterns are finite and one-third are chains; there is a single ring pattern, which occurs about a center of symmetry.
authors.affiliation: Department of Chemistry, Ohio State University, Columbus 43210, USA.
authors.forename: A J
authors.initials: AJ
authors.lastname: Dobson
authors.forename: R E
authors.initials: RE
authors.lastname: Gerkin
mesh_terms: D000621:Aminoisobutyric Acids / Q000737:chemistry*; D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D015394:Molecular Structure
chemical_list: D000621:Aminoisobutyric Acids; C033435:3-aminoisobutyric acid