Guanidine-Based Covalent Organic Frameworks: Cooperation between Cores and Linkers for Chromic Sensing and Efficient CO2 Conversion

Peng-Fei Mu; Lin Zhang; Ran Bu; Li-Fei Xiong; Ya-Wei Liu; En-Qing Gao

doi:10.1021/acsami.2c20510

Guanidine-Based Covalent Organic Frameworks: Cooperation between Cores and Linkers for Chromic Sensing and Efficient CO₂ Conversion

ACS Appl Mater Interfaces. 2023 Feb 8;15(5):6902-6911. doi: 10.1021/acsami.2c20510. Epub 2023 Jan 24.

Authors

Peng-Fei Mu¹, Lin Zhang¹, Ran Bu¹, Li-Fei Xiong¹, Ya-Wei Liu¹, En-Qing Gao^{1

2}

Affiliations

¹ Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China.
² Institute of Eco-Chongming, Shanghai 202162, China.

PMID: 36694474
DOI: 10.1021/acsami.2c20510

Abstract

C(sp)-H carboxylation with CO₂ is an attractive route of CO₂ utilization and is traditionally promoted by transition metal catalysts, and organocatalysis for the conversion remains rarely explored and challenging. In this article, triaminoguanidine-derived covalent organic frameworks (COFs) were used as platforms to develop heterogeneous organocatalysts for the reaction. We demonstrated that the COFs with guanidine cores and pyrazine linkers show high catalytic performance as a result of the cooperation between cores and linkers. The core is vitally important, which is deprotonated to the guanidinato group that binds and activates CO₂. The pyrazine linker collaborates with the core to activate the C(sp)-H bond through hydrogen bonding. In addition, the COFs show acid- and base-responsive chromic behaviors thanks to the amphoteric nature of the core and the auxochromic effect of the pyrazine linker. The work opens up new avenues to organocatalysts for C-H carboxylation and chromic materials for sensing and switching applications.

Keywords: CO2 utilization; COFs; C−H carboxylation; chromism; heterogeneous catalysis; organocatalysis.