title: Free radical reactions in two dimensions: a case study on photochlorination of graphene.
abstract: Graphene, a two-dimensional giant-molecule of sp(2) -bonded carbon atoms, provides a perfect platform for studying free radical reaction chemistry in two-dimensions, which holds promise to control the chemical functionality of graphene. Free-radical photochlorination of graphene is used as an example to investigate the thickness, stacking order, and single- and double-side dependent reactivity in graphene. Anomalously low reactivity is observed in the photochlorination of AB-stacked bilayer graphene in comparison with that of few-layer graphene. Double-sided chlorination of graphene shows higher reactivity and chlorine coverage than single-sided reaction. It is also experimentally and theoretically demonstrated that chlorine free radicals at low coverage prefer to form a stable charge-transfer complex with graphene, which highly enhances graphene's conductivity and simultaneously generates a pseudo-bandgap through noninvasive doping. Moreover, the initial accumulation of chlorine radicals is considered as the rate-determining step of photochlorination of graphene.
authors.affiliation: Center for Nanochemistry, Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China.
authors.forename: Lin
authors.initials: L
authors.lastname: Zhou
authors.forename: Lushan
authors.initials: L
authors.lastname: Zhou
authors.forename: Mingmei
authors.initials: M
authors.lastname: Yang
authors.forename: Di
authors.initials: D
authors.lastname: Wu
authors.forename: Lei
authors.initials: L
authors.lastname: Liao
authors.forename: Kai
authors.initials: K
authors.lastname: Yan
authors.forename: Qin
authors.initials: Q
authors.lastname: Xie
authors.forename: Zhirong
authors.initials: Z
authors.lastname: Liu
authors.forename: Hailin
authors.initials: H
authors.lastname: Peng
authors.forename: Zhongfan
authors.initials: Z
authors.lastname: Liu