| Affiliation: | 1. College of Materials, Xiamen University, Xiamen, 361005 P. R. China
Department of Pharmacology, Medical College, Wuhan University of Science and Technology, Wuhan, 430070 P. R. China;2. College of Materials, Xiamen University, Xiamen, 361005 P. R. China;3. College of Chemistry and Materials Science, Anhui Normal University, Wuhu, 241000 P. R. China;4. Collaborative Innovation Center of Chemistry for Energy Materials, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005 P. R. China;5. Institute of Physics, Chinese Academy of Sciences, Beijing, 100190 P. R. China;6. Department of Physics, Research Institute for Biomimetics and Soft Matter, Fujian Provincial Key Laboratory for Soft Functional Materials, Xiamen University, Xiamen, 361005 P. R. China |
| Abstract: | Radicals are closely related to human life and health and have been widely used in biology, chemistry, functional materials, etc. However, the high reactivity, disorder, and short half-lives limit their wide applications. Therefore, it remains a great challenge to prepare stable and ordered radicals. Herein, radicals are prepared with protective umbrellas (diethylmethyleneamine, DEMA) that are integrated on the surface of 2D layered materials to isolate water and oxygen and enhance the stability of radicals. Taking 2D black phosphorus (BP) as an example: triethylamine reacts with dichloromethane to form quaternary ammonium salts with further Hoffmann elimination to produce DEMA radicals that could react with one electron of a lone pair electrons in P on the surface of BP to produce P radicals, which shows a prolonged half-life of 21 days at room temperature. First-principle calculations and electron paramagnetic resonance fitting confirm that the steric hindrance constructed by dense DEMA passivation layer acts as a protective umbrella and the 2D coupling of P radicals and other P atoms in 2D BP plane to enhance the stability and strong superexchange interaction of P radicals. Furthermore, it is a general strategy to produce stable radicals integrated on the 2D plane. |
