Two polymeric structures with a benzene-1,2,4,5-tetracarboxylate ligand acting in mu(2)- and mu(4)-bridging modes

Abstract

catena-Poly[[tetraaquabis(1H-pyrazole-kappa N-2) nickel(II)] [[diaquabis(1H-pyrazole-kappa N-2) nickel(II)]-mu-benzene-1,2,4,5-tetracarboxylato-kappa O-2(1):O-4] tetrahydrate], {[Ni(C3H4N2)(2)(H2O)(4)][Ni(C10H2O8)(C3H4N2)(2)(H2O)(2)]center dot 4H(2)O}(n), (I), and poly[[(mu(4)-benzene-1,2,4,5-tetracarboxylato-kappa(4) O-1:O-2:O-4:O-5) octakis(1H-pyrazole-kappa N-2) dicobalt(II)] tetrahydrate], {[Co-2(C10H2O8)(C3H4N2)(8)]center dot 4H(2)O}(n), (II), are polymeric compounds crystallizing in the space group P (1) over bar, with two independent metallic cations and one benzene-1,2,4,5-tetracarboxylate (btc) anion, each lying on symmetry centres. Individual coordination polyhedra are regular and the main differences are in the way the btc anion binds [mu(2) in (I) and mu(4) in (II)], promoting a 'chain-like' one-dimensional structure in (I) and a 'sieve-like' two-dimensional motif in (II).