title: Tris(4-hydroxy-pyridinium) hydrogen sulfate-sulfate monohydrate.
abstract: In the crystal structure of the title salt, 3C(5)H(6)NO(+)·HSO(4) (-)·SO(4) (2-)·H(2)O, the hydrogen sulfate ion is linked to the sulfate ion by an O-H⋯O hydrogen bond. The hydrogen sulfate-sulfate anion is a hydrogen-bond acceptor for the three independent cations and the uncoordinated water mol-ecule, the hydrogen-bonding inter-actions giving rise to a three-dimensional hydrogen-bonded network. In the hydrogen sulfate-sulfate species, one of the sulfate groups is disordered in respect of its O atoms in a 2:1 ratio.
authors.forename: Ying-Ming
authors.initials: YM
authors.lastname: Xu
authors.forename: Shan
authors.initials: S
authors.lastname: Gao
authors.forename: Seik Weng
authors.initials: SW
authors.lastname: Ng