Boron difluoride formazanate copolymers with 9, 9-di-n-hexylfluorene prepared by copper-catalyzed alkyne–azide cycloaddition chemistry. Issue 21 (5th May 2016)

• Record Type: Journal Article
• Authors: Barbon, Stephanie M.; Gilroy, Joe B.
• Is Part Of: Polymer chemistry. Volume 7:Issue 21(2016)
• Page Start: 3589
• Page End: 3598
• Publication Date: 2016-05-05
• Subjects: Polymers -- Periodicals; Macromolecules -- Periodicals; Polymerization -- Periodicals; 547.705
• DOI: 10.1039/c6py00441e
• Languages: English
• ISSNs: 1759-9954

Abstract

Abstract : The synthesis and characterization of copolymers with promising light-harvesting properties and closely related model compounds based on boron difluoride formazanate and 9, 9-di- n -hexylfluorene units are described. Abstract : The synthesis and characterization of copolymers based on boron difluoride formazanate (BF2 L ) and 9, 9-di- n -hexylfluorene (hex2 Fl ) units are described. A series of model compounds [(BF2 L)-(hex2 Fl), (hex2 Fl)-(BF2 L)-(hex2 Fl), and(BF2 L)-(hex2 Fl)-(BF2 L) ] were also studied in order to fully understand the spectroscopic properties of the title copolymers[(BF2 L)-(hex2 Fl)] n . The model compounds and copolymers, which were synthesized by copper catalyzed alkyne–azide cycloaddition chemistry, exhibited high molar absorptivities (25 700–54 900 M −1 cm −1 ), large Stokes shifts (123–143 nm, 3590–3880 cm −1 ), and tunable electrochemical behaviour ( ca. −0.75 V and ca. −1.86 V vs. ferrocene/ferrocenium). The low-energy wavelength of maximum absorption and emission of the model compounds red-shifted relative to theBF2 L repeating unit by ca. 30 nm per triazole ring formed, to maximum values of 557 nm and 700 nm in DMF, respectively. The low-energy absorption and emission properties of the copolymer were consistent with the model compound bearing two triazole rings [(hex2 Fl)-(BF2 L)-(hex2 Fl) ] and were not dependent on copolymer molecular weight. However, the title copolymers may show promise as light-harvesting materials based on their thin-film optical band gap of 1.67 eV.