A new building block with intramolecular D-A character for conjugated polymers: ladder structure based on B←N unit  

作　　者：Xingxin Shao Chuandong Dou Jun Liu Lixiang Wang 

机构地区：[1]State Key Laboratory of Polymer Physics and Chemistry,Changchun Institute of Applied Chemistry,Chinese Academy of Sciences,Changchun 130022,China [2]University of Science and Technology of China,School of Applied Chemistry and Engineering,Hefei 230026,China

出　　处：《Science China Chemistry》2019年第10期1387-1392,共6页中国科学（化学英文版）

基　　金：supported by the National Natural Science Foundation of China (21625403, 21822507, 21875244, 21761132020, 21574129);National Key Research and Development Program of China (2018YFE0100600);funded by MOST and Strategic Priority Research Program of CAS (XDB12010200);Youth Innovation Promotion Association of CAS (2017265);State Key Laboratory of Supramolecular Structure and Materials in Jilin University (sklssm201905)

摘　　要：The general strategy to construct D-A type conjugated polymers is alternating copolymerization of electron-donating(D)monomer and electron-accepting(A)monomer.In this article,we report a new strategy to develop D-A type conjugated polymers,i.e.first fuse the D and A units into a polycyclic structure to produce a building block and then polymerize the building block with another unit.We develop a new building block with ladder structure based on B←N unit,B←N bridged dipyridylbenzene(BNDPB).In the skeleton of BNDPB,one diamine-substituted phenylene ring(D unit)and two B←N-linked pyridyl rings(A unit)are fused together to produce the polycyclic structure.Owning to the presence of intramolecular D-A character,the building block itself exhibits narrow bandgap of 1.74 eV.The conjugated polymers based on BNDPB show unique electronic structures,i.e.localized HOMOs and delocalized LUMOs,which are rarely observed for conventional D-A conjugated polymers.The polymers exhibit smaller bandgap than that of the building block BNDPB and display near-infrared(NIR)light absorption(λabs=ca.700 nm).This study thus provides not only a new strategy to design D-A conjugated polymers but also a new kind of building block with narrow bandgap.The general strategy to construct D-A type conjugated polymers is alternating copolymerization of electron-donating(D)monomer and electron-accepting(A) monomer. In this article, we report a new strategy to develop D-A type conjugated polymers, i.e. first fuse the D and A units into a polycyclic structure to produce a building block and then polymerize the building block with another unit. We develop a new building block with ladder structure based on B←N unit, B←N bridged dipyridylbenzene(BNDPB). In the skeleton of BNDPB, one diamine-substituted phenylene ring(D unit) and two B←N-linked pyridyl rings(A unit) are fused together to produce the polycyclic structure. Owning to the presence of intramolecular D-A character, the building block itself exhibits narrow bandgap of 1.74 eV. The conjugated polymers based on BNDPB show unique electronic structures, i.e. localized HOMOs and delocalized LUMOs, which are rarely observed for conventional D-A conjugated polymers. The polymers exhibit smaller bandgap than that of the building block BNDPB and display near-infrared(NIR)light absorption(λabs=ca. 700 nm). This study thus provides not only a new strategy to design D-A conjugated polymers but also a new kind of building block with narrow bandgap.

关 键 词：D-A CHARACTER conjugated polymers building BLOCK ladder structure B-N UNIT 

分 类 号：G63[文化科学—教育学]