title: Tetra-ethyl-ammonium 4-hy-droxy-benzoate monohydrate.
abstract: In the title compound, C(8)H(20)N(+)·C(7)H(5)O(3) (-)·H(2)O, the carboxyl-ate group is slightly out of the plane of the parent benzene ring, the C-C-C-O torsion angles being 2.3 (2) and 2.0 (2)°. The carboxyl-ate group and the hy-droxy group form O-H⋯O hydrogen bonds, generating a head-to-tail chain along the b axis. Neighbouring hydrogen-bonded chains are linked by the water mol-ecule, generating two independent O-H⋯O donor hydrogen bonds. The carboxyl-ate group thus constructs a hydrogen-bonded host layer parallel to (10[Formula: see text]). The tetra-ethyl-ammonium cation is contained between these layers, forming a sandwich-like structure with an approximate inter-layer distance of 10.03 Å.
authors.forename: Heping
authors.initials: H
authors.lastname: Li
authors.forename: Pei
authors.initials: P
authors.lastname: Liu
authors.forename: Yunxia
authors.initials: Y
authors.lastname: Yang