Syntheses, crystal structures and properties of a series of 3D cadmium coordination polymers with different topologies

Hydrothermal reactions of 2-, 3-, 4-cyanopyridine, NaN3 with CdCl2 in basified solvents yielded three coordination polymers [Cd-3(2-pytta)(2)(N-3)(4)(H2O)(2)](n) (1), [Cd(3-pytta)(2)](n) (2), [Cd-3(4-pytta)(2)(N-3)(2)Cl-2 (H2O)(4)] n (3). A similar reaction of tetrazole as ligand and the CdCl2 being replaced by CdI2 resulted in polymer [Cd-2(tta)(3)I](n) (4). X-ray single crystal structural analyses revealed that four compounds all show three-dimensional architectures. Complex 1 exhibits rare 3,4,4-connected 3-nodal with (3.9(2))(2)(3.9(4).10) (3(2).9(3).10)network in the Schafli notation, while complex 2 is an anatase net with 3,6-connected (4(2).6)(2)(4(4).6(2).8(8).10)network. Complex 3 is 3,3,4,4-connected 4-nodal network with (4.10(2))(2)(4(2).10(4)) (4(2).6.10(2).12)(2)(42.6)(2) topology, and complex 4 can be simplified as an interesting alpha-Po network. The solid emission spectra of 1, 2, 3 and 4 have also been studied. From the results, it can be found complex 4 exhibits a long triplet lifetime that is unusual in Cd-II complexes. (C) 2010 Elsevier B. V. All rights reserved.