title: Nonapiperidinium monohydrogen deca-vanadate tetra-nitrate.
abstract: The title compound, (C(5)H(12)N)(9)[HV(10)O(28)](NO(3))(4), contains a monoprotonated deca-vanadate polyanion which lies on an inversion center. All the piperidinium cations adopt chair conformations. In the crystal structure, inter-molecular N-H⋯O hydrogen bonds form chains along [001]. As well as half of a polyanion, the asymmetric unit contains one full and two half-occupancy nitrate ions and four full occupancy and one half-occupancy piperidinium cations; the half-occupancy piperidinium cation is disordered over two general sites with occupancies of 0.32 and 0.18, and is, in turn, disordered over an inversion center.
authors.affiliation: Laboratoire de Matériaux et de Cristallochimie, Faculté des Sciences de Tunis, Université de Tunis-El Manar, 2092 El Manar II Tunis, Tunisia.
authors.forename: Mohsen
authors.initials: M
authors.lastname: Graia
authors.forename: Regaya
authors.initials: R
authors.lastname: Ksiksi
authors.forename: Ahmed
authors.initials: A
authors.lastname: Driss