[Chem. Eur. J.] Chemoselective Phototransformation of C-H Bond on Polymer Surface via a Novel Photoinduced Cerium Recycling Redox
writer：Zhenhua Huang, Zhengfang Wu, Peng Yang* and Wantai Yang*
keywords：Surface modification, Cerium, Photooxidation, C-H activation, Carbohydrate Microarray
source：期刊
specific source：Chemistry A European Journal
Issue time：2014年
It is
generally accepted that Ce4+ is unable to directly oxidize inert
alkyl C-H bond without the assistance of adjacent polar groups. Herein we
demonstrated in our newly developed confined photochemical reaction system,
this recognition might be challenged. As we found, when a thin layer of CeCl3/HCl
aqueous solution was applied onto polymeric substrate, and under UV
irradiation, Ce3+ was firstly photooxidized into Ce4+ in
the presence of H+, and then in
situ formed Ce4+ could perform oxidation reaction on C-H bonds
of polymer surface to form active surface carbon radical for further radical
graft polymerization as well as functional group transformation, meanwhile
reduced itself to Ce3+ status with releasing H+. This
photoinduced cerium recycling redox (PCRR) actually behaved as a biomimetic
system towards an artificial recycling reaction, leading to a sustainable
chemical modification strategy for directly transforming alkyl C-H bond on
polymer surfaces to small molecular group and polymer brushes. This method is
expected to provide a green and economical tool for industrial applications of
polymer surface modification.