Ortho-Alkoxy-benzamide Directed Formation of a Single Crystalline Hydrogen-bonded Crosslinked Organic Framework and Its Boron Trifluoride Uptake and Catalysis

Fangzhou Li; Errui Li; Krishanu Samanta; Zhaoxi Zheng; Lianqian Wu; Albert D Chen; Omar K Farha; Richard J Staples; Jia Niu; Klaus Schmidt-Rohr; Chenfeng Ke

doi:10.1002/anie.202311601

Ortho-Alkoxy-benzamide Directed Formation of a Single Crystalline Hydrogen-bonded Crosslinked Organic Framework and Its Boron Trifluoride Uptake and Catalysis

Angew Chem Int Ed Engl. 2023 Dec 11;62(50):e202311601. doi: 10.1002/anie.202311601. Epub 2023 Nov 8.

Authors

Affiliations

¹ Department of Chemistry, Dartmouth College, Hanover, NH 03755, USA.
² Department of Chemistry, Brandeis University, Waltham, MA 02453, USA.
³ Department of Chemistry, Boston College, Chestnut Hill, MA 02467, USA.
⁴ Department of Chemistry, Northwestern University, Evanston, IL 60208, USA.
⁵ Department of Chemistry, Michigan State University, East Lancing, MI 48824, USA.

PMID: 37870901
DOI: 10.1002/anie.202311601

Abstract

Boron trifluoride (BF₃ ) is a highly corrosive gas widely used in industry. Confining BF₃ in porous materials ensures safe and convenient handling and prevents its degradation. Hence, it is highly desired to develop porous materials with high adsorption capacity, high stability, and resistance to BF₃ corrosion. Herein, we designed and synthesized a Lewis basic single-crystalline hydrogen-bond crosslinked organic framework (H_C OF-50) for BF₃ storage and its application in catalysis. Specifically, we introduced self-complementary ortho-alkoxy-benzamide hydrogen-bonding moieties to direct the formation of highly organized hydrogen-bonded networks, which were subsequently photo-crosslinked to generate H_C OFs. The H_C OF-50 features Lewis basic thioether linkages and electron-rich pore surfaces for BF₃ uptake. As a result, H_C OF-50 shows a record-high 14.2 mmol/g BF₃ uptake capacity. The BF₃ uptake in H_C OF-50 is reversible, leading to the slow release of BF₃ . We leveraged this property to reduce the undesirable chain transfer and termination in the cationic polymerization of vinyl ethers. Polymers with higher molecular weights and lower polydispersity were generated compared to those synthesized using BF₃ ⋅ Et₂ O. The elucidation of the structure-property relationship, as provided by the single-crystal X-ray structures, combined with the high BF₃ uptake capacity and controlled sorption, highlights the molecular understanding of framework-guest interactions in addressing contemporary challenges.

Keywords: BF3 Sorption; Controlled BF3 Release for Polymerization; Hydrogen-Bonded Crosslinked Organic Framework; Self-Complementary Hydrogen Bonding; Single-Crystal to Single-Crystal Transformation.

Abstract

Grants and funding