Abstract

catena-Poly[[tetra-aqua-bis(1H-pyrazole-N 2)nickel(II)] [[di-aqua-bis(1H-pyrazole-N 2)nickel(II)] - ben-zene-1,2,4,5-tetra- carboxyl-ato- 2 O 1:O 4] tetra-hydrate], {[Ni(C3H4N2)2(H2O)4][Ni(C10H2O8)(C3H4N2)2(H2O)2]·4H2O} n , (I), and poly[[(4-benzene-1,2,4,5-tetra-carboxyl-ato- 4 O 1:O 2:O 4:O 5)octa-kis(1H-pyrazole-N 2)dicobalt(II)] tetra-hydrate], {[Co2(C10H2O8)(C3H4N2)8]·4H2O} n , (II), are polymeric compounds crystallizing in the space group P , with two independent metallic cations and one benzene-1,2,4,5-tetra-carboxyl-ate (btc) anion, each lying on symmetry centres. Individual coordination polyhedra are regular and the main differences are in the way the btc anion binds [2 in (I) and 4 in (II)], promoting a chain-like one-dimensional structure in (I) and a sieve-like two-dimensional motif in (II). © 2009 International Union of Crystallography.