A polar tetrazolyl-carboxyl microporous Zn(II)-MOF: sorption and luminescent properties

A Zn(II)-MOF [Zn-2(tzba)(DMF)]center dot 0.5DMF (1) (H(2)tzba = 4-(1H-tetrazol-5-yl) benzoic acid, DMF = N,N'-dimethylformamide) has been solvothermally synthesized and characterized. 1 is a three-dimensional (3D) microporous framework possessing an unusual multi-nodal (3,3,6)- or (4,4,4,4)-connected topological net. The small-sized pores, open metal sites, phenyl pi systems and tetrazolyl groups of tzba(2-) decorating the pore with high polarity enable 1 to attract strongly for CO2, which leads to high sorption heat for CO2 and significant selectivities for CO2 over H-2 and N-2. In addition, 1 and desolvated 1' display strong and weak blue luminescence in solid state, respectively, being mainly related to the framework vibration due to the residing and releasing of DMF molecules in the channel.