Guest selectivity of a porous tetrahedral imidazolate framework material during self-assembly

Abstract

Presented here is the unusual guest selectivity observed in the self-assembly process of a porous tetrahedral imidazolate framework material [Zn(ad)(int)] (TIF-1, ad = adeninate, int = isonictinate). Four distinct solvent molecules, such as N,N-dimethylformamide (DMF), ethyleneurea (e-urea), N-methy1-2-pyrrolidone (NMP) and N,N-dimethylacetamide (DMA), can be trapped in the same in situ generated TIF-1 framework, respectively, which are identified by single-crystal X-ray diffraction. Complicated mixed solvent systems are investigated to understand the guest selectivity of TIF-1. The results reveal TIF-1 has strict guest selectivity following the sequence DMF > e-urea > NMP > DMA. Moreover, the activated TIF-1 after methanol-exchange exhibits high H₂ and CO₂ adsorption capacity and remarkable selectivity of CO₂ over N₂.