Zinc and Cadmium Diphenate Coordination Polymers with Conformationally Flexible Dipyridylamide Ligands

Zinc and cadmium diphenate (dip, biphenyl-2,2′-dicarboxylate) coordination polymers containing conformationally flexible dipyridylamide ligands show diverse chain and layer topologies as determined by single-crystal X-ray diffraction. [Cd(dipH)2(bdin)]n (1) [bdin = N,N′-(butane-1,3-diyl)diisonicotinamide] shows a simple 1D zigzag chain structure. {[Cd(dip)(pdin)(H2O)]·1.25H2O}n (2) [pdin = N,N′-(propane-1,3-diyl)diisonicotinamide] shows bilayer slabs formed by interleaving of (4,4) rectangular grid layers. {[Zn2(dip)2(3-pna)2]·3H2O}n (3) (3-pna = 3-pyridylnicotinamide) manifests a rare 4-connected 1D ribbon topology. {[Cd(dip)(4-ppbp)]·2H2O}n (4) [4-ppbp = propane-1,3-diylbis(piperidine-4,1-diyl)bis(pyridin-4-ylmethanone)] shows a 3,5-connected layer with (426)(42678) 3,5L2 topology. {[Zn4(dip)4(H2O)2(4-ppbp)2]·12H2O}n (5) exhibits 2D 3,6-connected layers with (43)2(466683) kgd topology featuring embedded R(8)A(2) classification 10-membered water clusters. Compounds 1, 4, and 5 undergo violet or blue-violet fluorescence upon ultraviolet irradiation. Thermal decomposition behavior of the new phases is also discussed.