Syntheses, Structures, and Physical Properties of Camphorate Coordination Polymers Controlled by Semirigid Auxiliary Ligands with Variable Coordination Positions and Conformations

A series of new coordination polymers, {[Zn(1,2-bimb)(D-ca)]center dot 2H(2)O}(n) (1), [Zn(1,3-bimb)(D-ca)](n) (2), [Cd(1,3-bimb)(D-ca)](n) (3), [Zn(1,4-bimb)(D-ca)](n) (4), and {[Cd-2(dpys)(D-ca)(2)(H2O)(2)]center dot H2O}(n) (5), (D-H(2)ca = D-camphoric acid, 1,2-bimb = 1,2-bis(imidazol-1-ylmethyl)-benzene, 1,3-bimb = 1,3-bis(imidazol-1-ylmethyl) -benzene, 1,4-bimb = 1,4-bis(imidazol-1-ylmethyl)-benzene, dpys = 4,4'-dipyridylsulfide), have been prepared under hydrothermal conditions and characterized by elemental analyses, IR, vibrational circular dichroism, thermogravimetric and X-ray structural analyses. Their structures and properties can be tuned by variable coordination positions and conformations of the auxiliary ligands. Complex 1 features a three-dimensional (3D) supramolecular framework with a one-dimensional (1D)-nanosized channel. Complexes 2 and 3 show acentric ID double-stranded chains. The chiral two-dimensional sheet with (4,4) topology is found in compound 4. Compound 5 displays a 1D ladderlike chain. Photoluminescent properties of 1 and 5 are studied. Compounds 2-5 display a second-order nonlinear optical effect and ferroelectric behaviors.