Harnessing Shape Complementarity for Upgraded Cyclohexane Purification through Adaptive Bottlenecked Pores in an Imidazole-Containing MOF

Angew Chem Int Ed Engl. 2021 Oct 25;60(44):23590-23595. doi: 10.1002/anie.202109964. Epub 2021 Oct 1.

Abstract

Shape complementarity is a biological craft for precisely binding substrates at protein-protein interfaces. An analogy to such a function can be drawn conceptually for crystalline porous solids; yet the manifested entities are rare in reticular chemistry. The bottleneck-shaped pores carved out of a metal-organic framework, Zn(MIBA)2 (aka. MAF-stu-13), can perfectly accommodate benzene molecules. Remarkably, its framework adapts to the optimal guest binding-the enhanced host-guest interactions in the neck in turn minimize the guest-guest repulsion in the pore to the extent it turns into attraction-as demonstrated by the combined X-ray structural and DFT computational studies. This adaptive material can be used for liquid-phase production of ultrahigh-purity (≥99 %) cyclohexane, achieving a balance between uptake capacity and separation selectivity and surpassing the performances of other porous and nonporous crystals reported recently (e.g. product purity 99.4 % vs. 97.5 % to date).

Keywords: adaptive crystals; host-guest chemistry; metal-organic frameworks; porous materials; separation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cyclohexanes / chemistry
  • Cyclohexanes / isolation & purification*
  • Imidazoles / chemistry*
  • Metal-Organic Frameworks / chemistry*
  • Models, Molecular
  • Particle Size

Substances

  • Cyclohexanes
  • Imidazoles
  • Metal-Organic Frameworks
  • Cyclohexane
  • imidazole