Mn^II-based MIL-53 Analogues: Synthesis Using Neutral Bridging μ₂-Ligands and Application in Liquid-Phase Adsorption and Separation of C6−C8 Aromatics

Abstract

Four Mn(II)-based MIL-53 single crystals were prepared using four neutral pyridine N-oxides as bridging mu(2)-ligands. In the case of 4,4'-bipridine-N,N'-dioxide (BPNO), the infinite manganese oxide chains were further interconnected by BPNO besides BDC, which allows 1D channels to be accessible for guest molecules. The liquid-phase adsorption and separation of C6-C8 aromatics using the evacuated compound as an absorbent were investigated via crystal-to-crystal transformations. Both structural evolution of the compounds and selectivity of C6-C7 aromatics of one evacuated compound could be attributed to noncovalent interactions, especially pi-pi interaction.