The effect of solvent system on the resulting structures of zeolitic imidazolate frameworks

Abstract

Two zeolitic imidazolate frameworks (ZIF) were synthesised from the same mixture of two imidazolate linkers resulting in two different topologies thanks to the use of different solvent systems. Zn(5-nbIm)0.33(2- mIm)1.67 (ZIF-HL1) and Zn(5-nbIm)1.14(2-mIm)0.86 (ZIFHL2), where 5-nbIm = 5-benzimidazolate and 2-mIm = 2-methylimidazolate, were prepared by the reaction of zinc nitrate hexahydrate with the mixture of 5-nbIm and 2-mIm in N,N-dimethylformamide (DMF) for ZIF-HL1 and DMF/acetonitrile (ACN)/water (4:3:1, v/v) for ZIFHL2. Their structures were determined by single-crystal X-ray diffraction, and their thermal behaviour and permanent porosity were also analysed. Accordingly, both structures exhibited high crystallization, thermal stability, and high porosity