Ammonium 4-(4-carboxyphenoxy)benzoate

The anions of the title salt, NH(4) (+)·HO(2)CC(6)H(4)-O-C(6)H(4)CO(2) (-), are linked by inter-molecular -CO(2)H⋯O(2)C- hydrogen bonds, forming a polyanionic chain in the crystal; adjacent chains are connected through the ammonium cation into a layer structure, with the ammonium cation serving as hydrogen-bond donor to four carboxyl-ate O atoms. The cation and anion both lie on special positions of 2 site symmetry. In the anion, the rings make a dihedral angle of 65.3 (1)°. The acid H atom is disordered about the special position.