title: Crystal structure of iso-butyl-ammonium hydrogen oxalate hemihydrate.
abstract: In the title hydrated mol-ecular salt, C4H12N(+)·C2HO4 (-)·0.5H2O, the O atom of the water mol-ecule lies on a crystallographic twofold axis. The dihedral angle between the CO2 and CO2H planes of the anion is 18.47 (8)°. In the crystal, the anions are connected to each other by strong near-linear O-H⋯O hydrogen bonds. The water mol-ecules are located between the chains of anions and iso-butyl-amine cations; their O atoms participate as donors and acceptors, respectively, in O-H⋯O and N-H⋯O hydrogen bonds, which form channels (dimensions = 4.615 and 3.387 Å) arranged parallel to [010].
authors.affiliation: Faculty of Chemistry, University of Opole, Oleska 48, 45-052 Opole, Poland.
authors.forename: Błażej
authors.initials: B
authors.lastname: Dziuk
authors.affiliation: Faculty of Chemistry, University of Opole, Oleska 48, 45-052 Opole, Poland.
authors.forename: Bartosz
authors.initials: B
authors.lastname: Zarychta
authors.affiliation: Faculty of Chemistry, University of Opole, Oleska 48, 45-052 Opole, Poland.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Ejsmont
keywords: crystal structure; hydrated mol­ecular salt; hydrogen bonding; iso­butyl­ammonium hydrogen oxalate hemihydrate; materials engineering