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)