Syntheses, Crystal Structures, and Luminescent Properties of Three Novel Zinc Coordination Polymers with Tetrazolyl Ligands

The syntheses and luminescent properties of three novel zinc coordination polymers containing tetrazolyl ligands are described. In situ [2+3] cycloaddition reactions of acetonitrile or p-tolylnitrile with sodium azide in the presence of Zn(ClO4)2 as a Lewis acid (Demko-Sharpless tetrazole synthesis method) under hydrothermal (solvothermal) reaction conditions gave [Zn(CH3CN4)2]3(H2O) (1) and [Zn(4-MPTZ)2] (3) [4-MPTZ = 5-(4-methylphenyl)tetrazole], respectively. On the other hand, [Zn(HCN4)2] (2) was obtained by directly reacting tetrazole with Zn(OAc)2 under hydrothermal reaction conditions. The structure of 1 shows a superdiamond-like topological network with a diamond subunit as a connecting node. For 2, a diamond-like topological network is also found, but it is 2-fold interpenetrated. The structure of 3 reveals a 2D layered network with a hexagonal net, with the adjacent layers in the network stacked in an ABAB sequence. Photoluminescence studies revealed coordination polymers 1, 2, and 3 exhibit strong blue fluorescent emissions at (lambda)max = 396, 418, and 397 nm, respectively, in the solid state at room temperature.