title: catena-Poly[bis-(4-amino-pyridinium) [[tetra-aqua-nickel(II)]-μ-benzene-1,2,4,5-tetra-carboxyl-ato] dihydrate].
abstract: The asymmetric unit of the title compound, {(C(5)H(7)N(2))(2)[Ni(C(10)H(2)O(8))(H(2)O)(4)]·2H(2)O}(n), contains an Ni(II) atom, two water mol-ecules of coordination, one half of a benzene-1,2,4,5-tetra-carboxyl-ate (btec) anionic ligand, one 4-amino-pyridinium cation (papy) and an uncoordinated water mol-ecule. The metal center lies on an inversion center and adopts an octa-hedral geometry with the carboxyl-ate groups tilted out of the mean plane formed by the btec. In the crystal, mol-ecules are linked into one-dimensional coordination polymers running along the ac diagonal. The crystal structure is consolidated by N-H⋯O and O-H⋯O hydrogen bonds.
authors.affiliation: Dipartimento di Chimica Inorganica, Chimica Analitica e Chimica Fisica, Universitá di Messina, Salita Sperone, 31-98166 Messina, Italy.
authors.forename: Archimede
authors.initials: A
authors.lastname: Rotondo
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Bruno
authors.forename: Fabio
authors.initials: F
authors.lastname: Messina
authors.forename: Francesco
authors.initials: F
authors.lastname: Nicoló