Syntheses, structures and luminescence of zinc and cadmium coordination polymers with bis(1,2,4-triazol-1-yl)butane and benzenedicarboxylate

The self-assembly reactions of the flexible ligand 1,4-bis(1,2,4-triazol-1-yl)butane (btb) and rigid ligand 1,4-benzenedicarboxylate (bdc) with Zn(II) or Cd(II) give two novel coordination polymers {[Zn(bdc)(btb)](H2O)5}n (1) and {[Cd2(bdc)2(btb)(H2O)2](H2O)7}n (2). Coordination polymer 1, a supramolecular isomer of [Zn2(bdc)2(btb)2](H2O)2 [X.L. Wang, C. Qin, E.B. Wang, Z.M. Su, Chem. Eur. J. 12 (2006) 2680], is a special 2D (6,3) network, with six Zn(II) atoms at six corners and four bdc and two double btb at six edges. Coordination polymer 2 exhibits a distorted 3D cubic topology that is built from dimer Cd2 units. The blue luminescent emission maxima at 420 and 439 nm for 1, 440 and 455 nm for 2 were observed in the solid state at room temperature.