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

Abstract

A Zn(II)–MOF [Zn₂(tzba)(DMF)]·0.5DMF (1) (H₂tzba = 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 π systems and tetrazolyl groups of tzba²⁻ 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 H₂ and N₂. 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.