Interleaved and entangled divalent metal thiophenedicarboxylate coordination polymers with an extremely long-spanning and flexible dipyridylamide ligand

Abstract Hydrothermal reaction of metal nitrates, 2,5-thiophenedicarboxylic acid (H 2 tdc) and the conformationally flexible and very long spanning dipyridylamide ligand propane-1,3-diylbis(piperidine-4,1-diyl)bis(pyridin-4-ylmethanone) (4-ppbp) produced three new coordination polymers which were structurally characterized by single-crystal X-ray diffraction. [Cu(tdc)(4-ppbp)(H 2 O)]·2H 2 O} n ( 1 ) manifests a slab topology with pairs of interleaved (4,4) layer motifs. [Co(tdc)(4-ppbp)(H 2 O)] n ( 2 ) shows a 2,4-connected 1-D tubular structure that engages in very rare 1D + 1D → 2D parallel polycatenation. [Ni(tdc)(4-ppbp) 2 (H 2 O)] n ( 3 ) possesses a unique system of 2D + 2D → 2D interpenetrated 2,6-connected layers, derived from the edge-crossed SP 2-periodic (4,4)IIb net, when O–H⋯N hydrogen bonding patterns are taken into account. The conformational flexibility of the 4-ppbp ligand affords the requisite loops for the unique polycatenation patterns in 2 and 3 . Thermal decomposition properties of these three new materials are discussed.