Using metal substrates to enhance the reactivity of graphene towards Diels–Alder reactions. Issue 34 (17th August 2022)

• Record Type: Journal Article
• Authors: Yang, Xiaojian; Chen, Feiran; Kim, Min A.; Liu, Haitao; Wolf, Lawrence M.; Yan, Mingdi
• Is Part Of: Physical chemistry chemical physics. Volume 24:Issue 34(2022)
• Page Start: 20082
• Page End: 20093
• Publication Date: 2022-08-17
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/d2cp01842j
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : The Diels–Alder reaction using both dienes and dienophiles on graphene is shown to be accelerated using metal substrates as determined from experimentally obtained rate constants and supported by DFT calculations. Abstract : The Diels–Alder (DA) reaction, a classic cycloaddition reaction involving a diene and a dienophile to form a cyclohexene, is among the most versatile organic reactions. Theories have predicted thermodynamically unfavorable DA reactions on pristine graphene owing to its low chemical reactivity. We hypothesized that metals like Ni could enhance the reactivity of graphene towards DA reactions through charge transfer. The results indeed showed that metal substrates enhanced the reactivity of graphene in the DA reactions with a diene, 2, 3-dimethoxy butadiene (DMBD), and a dienophile, maleic anhydride (MAH), with the activity enhancement in the order of Ni > Cu, and both are more reactive than graphene supported on silicon wafer. The rate constants were estimated to be two times higher for graphene supported on Ni than on silicon wafer. The computational results support the experimentally obtained rate trend of Ni > Cu, both predicted to be greater than unsupported graphene, which is explained by the enhanced graphene–substrate interaction reflected in charge transfer effects with the strongly interacting Ni. This study opens up a new avenue for enhancing the chemical reactivity of pristine graphene through substrate selection.