A microporous Zn(ii)–MOF with open metal sites: structure and selective adsorption properties

Abstract

A three-dimensional microporous framework, Zn(II)–MOF [Zn(HPyImDC)(DMA)]_n (1) (H₃PyImDC = 2-(pyridine-4-yl)-1H-4,5-imidazoledicarboxylic, DMA = N,N′-dimethylacetamide), with open metal sites and small-sized pores, exhibits excellent selective capture of CO₂ over N₂ and CH₄ at 273 K, as well as alcohols from water. The excellent CO₂ adsorption selectivity of 1 allows its potential use in the capture of CO₂ from industrial flue gas or the removal of CO₂ from natural gas. More interestingly, compound 1 represents the rare case of porous materials separating propanol isomers, which may be caused by the relative flexibility of the linear n-propanol considering that both n-propanol and i-propanol have similar kinetic diameters.