title: 2-Bromo-maleic acid.
abstract: The title compound, C(4)H(3)BrO(4), was obtained from a solution of meso-2,3-dibromo-succinic acid and vanadium(IV) oxide. The crystals are isostructural with chloro-maleic acid and the mol-ecule has two geometrically different carboxyl groups, one of which has delocalized C-O bonds and is essentially coplanar with the olefinic bond plane [give dihedral angle 15.08 (16)°], whereas the other has a localized C=O bond and forms a dihedral angle of 99.6 (3)° with the C=C bond plane. Two symmetry-independent O-H⋯O hydrogen bonds link the mol-ecules into layers parallel to the bc plane.
authors.affiliation: Inorganic Chemistry, School of Chemical Science and Engineering, Royal Institute of Technology (KTH), 100 44 Stockholm, Sweden.
authors.forename: Andreas
authors.initials: A
authors.lastname: Fischer