Cadmium-Based Coordination Polymers from 1D to 3D: Synthesis, Structures, and Photoluminescent and Electrochemiluminescent Properties

Cadmium-based coordination polymers, namely, {[Cd(HL)(L)]center dot HN(Et)(3)}(n) (1), [Cd-2(L)(2)(H2O)(5)](n) (2), [Cd(L)(phen)](n) (3), [Cd(L)(2,2 '-bpy)](n) (4), [Cd(L)(4,4 '-bpy)](n) (5), [Cd(L)(bpp)](n) (6), [Cd(L)(dpa)](n) (7), {[Cd(L)(dpa)]center dot H2O}(n) (8) (H2L=4,4 '-((p-tolylazanediyl)bis(methylene))dibenzoic acid, phen=1,10-phenanthroline, 2,2 '-bpy=2,2 '-bipyridine, 4,4 '-bpy=4,4 '-bipyridine, bpp=1,3-bis(4-pyridyl)propane, dpa=bis(4-pyridyl)amine) have been synthesized in hydro/solvothermal reactions. 1 is a 4-connect 3D network with an eightfold interpenetrating diamond topology. The 1D ladder chain structure of 2 was composed of the dinuclear [Cd-2(CO2)(4)] subunit bridged with two L2- ligands. 3 shows a 1D double-chain with a channel formed by edging out the coordination water with the rigid co-ligand phen. Polymer 4 displays a 2D lamellar structure based on superseding the coordination water molecules by the rigid chelating auxiliary ligands 2,2 '-bpy. By substituting the small molecules with a rigid bridging ligand 4,4 '-bpy, a 2D undulating structure of 5 was built. Compounds 6 and 7 exhibit a 2D layer structure with a 4-connect (4(4)center dot 6(2)) sql-net. Compound 8 presents a 3D architecture with a sixfold interpenetrating diamond topology. Through our construction strategy, versatile structures from 1D-3D have been rationally designed by controlling the process condition and rigid/flexible of N-donor spacers. Additionally, the photoluminescence, charge transfer, and electrochemical luminescence (ECL) properties of 1-8 have been demonstrated.