title: Chemoselective phototransformation of C-H bonds on a polymer surface through a photoinduced cerium recycling redox reaction.
abstract: It is generally accepted that Ce(4+) is unable to directly oxidize unreactive alkyl C-H bonds without the assistance of adjacent polar groups. Herein, we demonstrate in our newly developed confined photochemical reaction system that this recognized issue may be challenged. As we found, when a thin layer of a CeCl(3)/HCl aqueous solution was applied to a polymeric substrate and the substrate subjected to UV irradiation, Ce(3+) was first photooxidized to form Ce(4+) in the presence of H(+), and the in situ formed Ce(4+) then performs an oxidation reaction on the C-H bonds of the polymer surface to form surface-carbon radicals for radical graft polymerization reactions and functional-group transformations, while reducing to Ce(3+) and releasing H(+) in the process. This photoinduced cerium recycling redox (PCRR) reaction behaved as a biomimetic system in an artificial recycling reaction, leading to a sustainable chemical modification strategy for directly transforming alkyl C-H bonds on polymer surfaces into small-molecule groups and polymer brushes. This method is expected to provide a green and economical tool for industrial applications of polymer-surface modification.
authors: The State Key Laboratory of Chemical Resource Engineering, College of Material Science and Engineering, Beijing University of Chemical Technology (BUCT), Beijing, 100029 (P. R. China), Fax: (+86) 10-64416338.
authors: Zhenhua
authors: Z
authors: Huang
authors: Zhengfang
authors: Z
authors: Wu
authors: Peng
authors: P
authors: Yang
authors: Wantai
authors: W
authors: Yang
keywords: CH activation; carbohydrate microarrays; cerium; photooxidation; surface modification