News Source & Photographer: School of Life Science

Editor: Xiao Wen

Reviewer: Zhou Lianjing

Recently, the Green bio-manufacturing team of Beijing Institute of Technology and Professor Chen Long's team of Jilin University published a review article on ionic liquids promoting the synthesis, function and application of porous organic framework materials. The relevant research results have been published in the top international journal Coordination Chemistry Reviews entitled "Ionic liquids promoted synthesis, enhanced functions, and expanded applications of porous organic frameworks". The co-first authors of this work are Li Wenjin, a PhD student in 2021, Xiao Wenzhe, a PhD student in 2022, and Luo Qizhen, a master student in 2021, are co-first authors, and the corresponding authors are Professor Chen Long from Jilin University and Professor Sun Jian from BIT, the first communication unit.

Metal organic framework (MOFs) and covalent organic framework (COFs) materials have attracted great attention in many fields such as heterogeneous catalysis, gas separation and sorption, electrochemical energy storage, chemical sensing and drug delivery due to their large specific surface area and designable structures. However, traditional synthesis strategies and intrinsic limitations limit their application potential. The introduction of ionic liquids (ILs) can provide an ideal ionic microenvironment or serve as active species to endow organic frameworks with additional functions. This work provides a new perspective on the role of ILs in porous organic frameworks based on the synthesis and applications of the porous organic frameworks (Figure 1).

Figure 1. The illustration of IL-incorporated MOFs/COFs and functions of composite materials.

This work first discusses the role of ILs in promoting the synthesis and modulating the functions of porous organic frameworks. ILs has excellent stability, low volatility, high gas affinity and good catalytic activity etc. Porous organic frame materials provide regular porosity and structural designability that facilitate ILs bonding to organic frameworks and enhance their functionality. In the synthetic process of porous organic frame materials, ILs can be used as solvent and post-synthetic modifier respectively to influence the structure and properties of the final material. At the same time, the combination of ILs with organic frame materials can enhance its function through the interaction of the two (such as hydrogen bonding, electrostatic or synergistic). For example, the introduction of ILs can not only confer fluidity on MOFs, but also enhance their electrical conductivity, adsorption capacity, and catalytic activity (Figure 2). Subsequently, this work further summarizes the advantages of ILs in improving the catalysis, energy storage and gas adsorption of porous organic frame materials.

Figure 2. Enhanced functions after incorporation of ILs in MOFs.

Finally, this work looks forward to the challenges and opportunities in the progressing field of ILs with porous organic frameworks. The author believes that the structure-activity relationship of ILs should be studied comprehensively by means of molecular simulation, experimental verification and spectral characterization. New combinations of potential ILs and MOFs or COFs can be attempted on the basis of new interaction modes, various existing forms (such as composites, membranes, fibers and spheres) and various application scenarios. In addition, the potential impacts of secondary pollutants on the environment, microorganisms and other organisms arising from the construction of the IL@MOF and IL@COF systems should be considered. This work will provide reference for the design of new ILs-MOFs/COFs materials.

Link to the article: https://doi.org/10.1016/j.ccr.2023.215304