Metal-Organic Coordination Polymers Generated from Chiral Camphoric Acid and Flexible Ligands with Different Spacer Lengths: Syntheses, Structures, and Properties

A new family of coordination polymers, [{Cd(D-ca)(bte)}center dot H2O](n) (1, D-H2Ca = D-camphor acid, bte = 1,2-bis(1,2,4-triazol-1-yl)ethane), [Cd-4(D-ca)(4)(btp)(2)(H2O)(4)](n) (2, btp = 1,3-bis(1,2,4-triazol-1-yl)propane), [{Cd(D-ca)(btb)(1.5)}center dot 3H(2)O](n) (3, btb = 1,4-bis(1,2,4-triazol-1-yl)butane), [{Cd-4(D-ca)(4)(bth)(4)}center dot 2H(2)O](n) (4, bth = 1,6-bis(1,2,4-triazol-1-yl)hexane), and [{Cd-(D-Hca)(2)(bth)(H2O)}center dot H2O](n) (5), have been prepared under hydrothermal conditions and characterized by elemental analyses, IR, thermogravimetric and X-ray structural analyses. The bis(triazole) ligands with different spacer lengths exhibit conformational flexibility and lead to the generation of diversified architectures. Complex 1 shows a two-dimensional (2D) rectangular network with (4,4) topology. Complex 2 displays the chiral three-dimensional (3D) framework with (3(2).4) (3.8(4).12) (8(3)) (4.8.10) topology. The 2D honeycomb motif with one-dimensional (1D) nanosized channels is found in compound 3. Compound 4 is a 2D parallelogram sheet with (4,4) topology. Compound 5 shows a chiral 1D fish-bone chain, and the chains are further connected through hydrogen-bonding interactions to form a 3D supramolecular framework. Their luminescent, second-order nonlinear optical and ferroelectric properties have been investigated in the solid state.