Metal-Directed Supramolecular Architectures: From Mononuclear to 3D Frameworks Based on In Situ Tetrazole Ligand Synthesis

This work focuses on the investigation of the influence of metal ions and supramolecular interactions on the self-assembly of in situ generated tetrazolate coordination architectures. A series of new metal−organic complexes, [Zn(pzta) 2 (H 2 O) 2 ] ( 1 ), [Cu(pzta) 2 ](H 2 O) 3 ( 2 ), [Cd(pzta) 2 ] n ( 3 ), [Ag(pzta)] n ( 4 ), and [Cd 2 (pzta)(OH)(SO 4 )] n ( 5 ) [pzta = pyrazinyl tetrazolate], have been achieved by the in situ hydrothermal reactions of pyrazinecarbonitrile, sodium azide, and different metal ions. Complexes 1 and 2 have similar mononuclear structures bearing distinct intermolecular hydrogen-bond interactions to form two different 3D supramolecular networks based on 4 4 -subnets. Complex 3 features a 1D crossed-shape chain structure. Complex 4 is a coordination polymer comprised of mildly undulated 2D layers with a (4.8 2 ) topological network. Complex 5 is a 3D diamondoid framework constructed by pentanuclear cadmium cluster nodes and pzta linkers. The configurations of complexes 1 − 5 span from mononuclear ( 1, 2 ), to one-dimensional ( 3 ) and two-dimensional ( 4 ), to three-dimensional ( 5 ), which indicates that metal ions play an essential role in the framework formation of the in situ generated tetrazolate architectures. Furthermore, complexes 1, 3, and 5 exhibit strong blue photoluminescence in similar energy regions.