Crystal structure of iso­butyl­ammonium hydrogen oxalate hemihydrate

In the title hydrated mol­ecular salt, C(4)H(12)N(+)·C(2)HO(4) (−)·0.5H(2)O, the O atom of the water mol­ecule lies on a crystallographic twofold axis. The dihedral angle between the CO(2) and CO(2)H 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 mol­ecules are located between the chains of anions and iso­butyl­amine 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].