Entangled zinc–ditetrazolate frameworks involving in situ ligand synthesis and topological modulation by various secondary N-donor ligands

The introduction of various secondary N-donor ligands into an in situ ditetrazolate-ligand synthesis system of terephthalonitrile, NaN3 and ZnCl2 led to the formation of three new entangled frameworks Zn(pdtz)(4,4′-bipy)·3H2O (1), [Zn(pdtz)(bpp)]2·3H2O (2) and Zn(pdtz)0.5(N3)(2,2′-bipy) (3) (4,4′-bipy=4,4′-bipyridine; bpp=1,3-bis(4-pyridyl)propane; 2,2′-bipy=2,2′-bipyridine; H2pdtz=5,5′-1,4-phenylene-ditetrazole). The formation of pdtz2− ligand involves the Sharpless [2+3] cycloaddition reaction between terephthalonitrile and NaN3 in the presence of Zn2+ ion as a Lewis-acid catalyst under hydrothermal conditions. Compound 1 exhibits a fivefold interpenetrating 3D framework based on the diamondoid topology. Compound 2 displays a twofold parallel interpenetrating framework based on the wavelike individual network. Compound 3 possesses a 2D puckered network. These new Zn–ditetrazolate frameworks are highly dependent on the modulation of different secondary N-donor ligands. Their luminescent properties were investigated.

Graphical abstractThree new entangled frameworks were prepared by an in situ ditetrazolate-ligand synthesis system assisted with various auxiliary N-donor ligands. The entangled structures can be modulated by different secondary ligands.Figure optionsDownload full-size imageDownload as PowerPoint slide