Rational Design of Metal-Organic Frameworks Based on 5-(4-Pyridyl)tetrazolate: From 2D Grids to 3D Porous Networks

The hydrothermal reactions of Zn(ClO4)2·6H2O/Cu(NO3)2·6H2O with 5‐(4‐pyridyl)tetrazole in an ethanol/water or ethanol/water/pyridine medium yield one 2D and one 3D metal‐organic coordination framework [Zn2(OH)(4‐ptz)3] (1) and [Cu(4‐ptz)·0.5(py)] (3) [4‐ptz = 5‐(4‐pyridyl)tetrazolate, py = pyridine], respectively. Complex 1 possesses two identical and independent rectangular grid sheets with twofold parallel interpenetration, in which the four‐connected nodes of the net are provided by Zn2(OH) units connected to one another through 4‐ptz and (4‐ptz)2 bridges. These composite sheets are stacked one on top of another by hydrogen‐bonding interactions to afford a 3D structure. There are many structural similarities between complex 1 and the recently reported 2D layered network [Zn(OH)(4‐ptz)(H2O)] (2), in particular the components of the network, the coordination mode of the 4‐ptz ligand and the in situ formation of hydroxy groups. Complex 2 can be synthesized by the hydrothermal reaction of Zn(ClO4)2·6H2O and 5‐(4‐pyridyl)tetrazole in an ethanol/water/pyridine medium. The structural characterization of complex 3 shows a porous structure that contains the guest pyridine molecules. Additionally, compounds 1 and 2 exhibit strong fluorescence at room temperature in the solid state. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)