title: 1,4-Dimethyl-piperazin-1-ium 3-hy-droxy-2-naphtho-ate.
abstract: The reaction of 1,4-dimethyl-piperazine and 3-hy-droxy-2-naphthoic acid gives the title 1:1 salt, C(6)H(15)N(2) (+)·C(11)H(7)O(3) (-), with a singly protonated piperazinium cation. In the crystal, a single N-H⋯O hydrogen bond links the cations and anions into discrete pairs and the aromatic anions stack along the crystallographic a-axis direction. This results in layers of cations and anions alternating along the crystallographic c-axis direction. An intra-molecular O-H⋯O hydrogen bond is also present.
authors.affiliation: Department of Pure and Applied Chemistry, WestCHEM, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL,  Scotland.
authors.forename: Gemma E
authors.initials: GE
authors.lastname: Craig
authors.forename: Carla
authors.initials: C
authors.lastname: Johnson
authors.forename: Alan R
authors.initials: AR
authors.lastname: Kennedy