1,1'-(Ethane-1,2-di-yl)dipyridinium bis-(1,2-di-cyano-ethene-1,2-di-thiol-ato-κ(2) S,S')cuprate(II).

In the title ion-pair complex, (C12H14N2)[Cu(C4N2S2)2], the complex anion exhibits a highly twisted coordination environment around the tetra-coordinated Cu(II) atom. The dihedral angles between the 1,2-di-cyano-ethene-1,2-di-thiol-ato ligands and between the two pyridine rings in the cation are 37.49 (3) and 29.18 (10)°, respectively. Weak C-H⋯N and C-H⋯S hydrogen bonds link the cations and anions into a three-dimensional network.

catena-Poly[[tetra-aqua-nickel(II)]-µ-(9,10-dioxo-9,10-dihydro-anthracene-1,4,5,8-tetra-carboxyl-ato)-κ(2)O(1):O(8)-[tetra-aqua-nickel(II)]-µ-4,4'-bipyridine-κ(2)N:N'].

In the crystal of the title polymeric complex, [Ni(2)(C(18)H(4)O(10))(C(10)H(8)N(2))(H(2)O)(8)](n), each Ni(II) cation is coord-in-ated by four water mol-ecules in the equatorial plane, and is further bridged by an 9,10-dioxo-9,10-dihydro-anthracene-1,4,5,8-tetra-carb-oxy-l-ate anion and a 4,4'-bipyridine ligand in the axial directions, forming a distorted octa-hedral geometry. The 9,10-dioxo-9,10-dihydro-anthracene-1,4,5,8-tetra-carboxyl-ate anion is centrosymmetric with the centroid of the quinone ring located about an inversion center; the 4,4'-bipyridine ligand is also centrosymmetric with the mid-point of the C-C bond linking two pyridine rings located about another invertion center. The 9,10-dioxo-9,10-dihydro-anthracene-1,4,5,8-tetra-carboxyl-ate anion and bypiridine ligand bridge the Ni(II) cations, forming a polymeric chain along the b axis. π-π stacking is observed between pyridine and benzene rings [centroid-centroid distance = 3.705 (2) Å]. All of the coordinating water mol-ecules are involved in O-H⋯O hydrogen bonding.