Reversible adsorption and separation of chlorocarbons and BTEX based on Cu(ii)-metal organic framework

Abstract

A new non-interpenetrating 2D Cu(II)-metal organic framework has been successfully synthesized from the carbazole-bridging organic ligand L and Cu(NO₃)₂ in solution. The CuL₂(NO₃)₂ framework contains square-like channels and the n-butyl groups on L face toward the channel center to form the typical hydrophobic pores. In addition, the reported CuL₂(NO₃)₂ host can reversibly upload various VOCs such as CH₂Cl₂, CHCl₃ and BTEX (benzene, toluene, ethylbenzene, o-xylene, m-xylene, and p-xylene) under ambient conditions without loss of framework integrity. Furthermore, it is able to effectively separate CH₂Cl₂ from CHCl₃, benzene from toluene/ethylbenzene/xylene and toluene from ethylbenzene/xylene in the liquid phase. The selectivity for chlorocarbons is derived from the substrate polarity, while the host–guest hydrophobic interaction might be the dominating factor for BTEX affinity.