Successive Free-Radical C(sp^(2))-C(sp^(2)) Coupling Reactions to Form Graphene  

作　　者：Huaqiang Cao Cheng Wang Baojun Li Tianyu Chen Peng Han Yan Zhang Haijun Yang Qunyang Li Anthony K.Cheetham 

机构地区：[1]Department of Chemistry,Tsinghua University,Beijing 100084 [2]Beijing Advanced Innovation Center for Imaging Technology and Key Laboratory of Terahertz Optoelectronics(MoE),Department of Physics,Capital Normal University,Beijing 100048 [3]Applied Mechanics Laboratory,Department of Engineering Mechanics,School of Aerospace Engineering,Tsinghua University,Beijing 100084 [4]Department of Materials Science and Metallurgy,University of Cambridge,Cambridge CB30FS [5]Materials Research Laboratory,University of California,Santa Barbara,Santa Barbara,CA 93106

出　　处：《CCS Chemistry》2022年第2期584-597,共14页中国化学会会刊（英文）

基　　金：This work was financially support from the National Key R&D Program of China(no.2016YFA0200200);the National Program on Key Basic Research Project(973 program,no.2013CB933804);the National Natural Science Foundation of China(no.21271112);the Tribology Science Fund of State Key Laboratory of Tribology(SKLTKF20B18).

摘　　要：Graphene is of great interest because of its exciting properties and potential applications,but its production on a large-scale still presents considerable challenges.Herein,we report the synthesis of predominately few-layer graphene,due toπ–πstacking,and single-layer graphene from reaction between hexabromobenzene and Na metal,followed by annealing to improve crystallinity.The reaction proceeds via a free-radical C(sp^(2))–C(sp^(2))coupling mechanism,which is supported by theoretical calculations.The graphene can host unpaired spin electrons,leading to a short acquisition time for a solidstate nuclear magnetic resonance 13C spectrum from unlabeled graphene,which is ascribed to the very short spin-lattice relaxation time.High catalytic activity for transforming amine to imine with a conversion of>99%and a yield of∼97%is demonstrated,and high electronic conductivity of∼105 S·m^(−1) is found by terahertz spectroscopy.The reaction delivers a method for synthesizing graphene with a high spin concentration from perbrominated benzene molecules by using an active metallic agent,such as Na,Li,or Mg.

关 键 词：graphene synthesis radical C(sp^(2))-C(sp^(2))coupling high electron spin density short spin-lattice relaxation metal-free amine conversion catalyst 

分 类 号：O62[理学—有机化学]