Thermally Responsive Selenide-containing Materials Based on Transalkylation of Selenonium Salts

Angew Chem Int Ed Engl. 2023 Dec 4;62(49):e202309652. doi: 10.1002/anie.202309652. Epub 2023 Oct 31.

Abstract

Covalent adaptable networks (CANs) possess unique properties as a result of their internal dynamic bonds, such as self-healing and reprocessing abilities. In this study, we report a thermally responsive C-Se dynamic covalent chemistry (DCC) that relies on the transalkylation exchange between selenonium salts and selenides, which undergo a fast transalkylation reaction in the absence of any catalyst. Additionally, we demonstrate the presence of a dissociative mechanism in the absence of selenide groups. After incorporation of this DCC into selenide-containing polymer materials, it was observed that the cross-linked networks display varying dynamic exchange rates when using different alkylation reagents, suggesting that the reprocessing capacity of selenide-containing materials can be regulated. Also, by incorporating selenonium salts into polymer materials, we observed that the materials exhibited good healing ability at elevated temperatures as well as excellent solvent resistance at ambient temperature. This novel dynamic covalent chemistry thus provides a straightforward method for the healing and reprocessing of selenide-containing materials.

Keywords: Covalent Adaptable Networks; Dynamic Covalent Chemistry; Selenide; Selenonium Salts; Transalkylation.