Chain, ladder and self-penetrated cobalt and nickel coordination polymers containing sterically bulky isophthalate and long-spanning dipyridylamide ligands

Hydrothermal reaction of cobalt or nickel nitrate with 5-tert-butylisophthalic acid (H(2)tbip) and bis(4-pyridylformyl) piperazine (bpfp) under varying synthetic conditions afforded four coordination polymers that were subsequently structurally characterized via single-crystal X-ray diffraction. {[Co(Htbip)(2)(H2O)(2)(bpfp)]center dot H2O}(n) (1), prepared with a lower concentration of added base, exhibits a 1D sawtooth chain structure. {[Co-2(tbip)(2)(H2O)(4)(bpfp)]center dot 2H(2)O}(n) (2), prepared under higher base conditions, and its analog {[Ni-2(tbip)(2)(H2O)(4)(bpfp)]center dot 2H(2)O}(n) (3), show isostructural 1D ladder topologies. {[Ni(tbip)(H2O)(2)(bpfp)]center dot 2.25H(2)O}(n) (4), prepared using a higher concentration of reactants than for 3, manifests an extremely rare 6(5)8 4T10 4-connected self-penetrated topology and represents the first metal dicarboxylate coordination polymer to possess this network. Thermal decomposition behavior of these materials is also discussed. (C) 2015 Elsevier B.V. All rights reserved.