title: 2-Ethyl-1H-imidazol-3-ium hemioxalate oxalic acid monohydrate.
abstract: In the title compound, C(5)H(9)N(2) (+)·0.5C(2)O(4) (2-)·C(2)H(2)O(4)·H(2)O, the anions, cations and water mol-eculars are linked by N-H⋯O and O-H⋯O hydrogen bonds which define a tightly bound three-dimensional structure. The title compound is a layered structure as viewed along the a or c axis; one layer contains water and oxalic acid mol-ecules, the other the imidazolium cation. The C atoms of the ethyl group of the 2-ethyl-imidazolium cation are disordered over two positions of equal occupancy.
authors.affiliation: Ordered Matter Science Research Center, College of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, People's Republic of China.
authors.forename: Run-Qiang
authors.initials: RQ
authors.lastname: Zhu