Two new 3D (3,8)-connected metal–organic frameworks based on zinc–triazole secondary building units and benzenetricarboxylate linkers

Two new zinc–triazole–carboxylate frameworks constructed from secondary building units (SBUs), [Zn5(trz)4(btc)2(DMF)2(H2O)2]·2H2O·DMF (1) and [Zn4(trz)3(btc)2(CH3CN)(H2O)]·5H2O·(Bu4N) (2), [Htrz = 1,2,4-triazole, H3btc = 1,2,4-benzenetricarboxylate, Bu4N = tetrabutylammonium], have been synthesized by solvothermal reactions and characterized by single-crystal X-ray diffraction analyses, X-ray power diffraction, elemental analyses, infrared spectra and thermogravimetric analyses. Both compounds 1 and 2 exhibit 3D (3,8)-connected tfz-d nets with {43}2{46.618.84} topology symbol built from rod-shaped {[Zn5(trz)4]6+}n SBUs (1) and {[Zn4(trz)3]5+}n SBUs (2). In two compounds, rodlike units are connected by btc ligands via different modes. Additionally, solid state fluorescent emission spectra of two compounds show fluorescent properties at room temperature.

Graphical abstractBoth compounds 1 and 2 exhibit 3D (3,8)-connected tfz-d nets, 1 consists of [Zn3(trz)4] cores linked through two Zn atoms to form rod-shaped {[Zn5(trz)4]6+}n SBUs, and 2 contains 3-fold paddle-wheels [Zn2(trz)3] cores which are connected by Zn to generate rod-shaped {[Zn4(trz)3]5+}n SBUs.Figure optionsDownload full-size imageDownload as PowerPoint slide