کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5403903 1505931 2007 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Temperature dependent spectroscopy of poly[9,9-bis-(2-ethyl)hexylfluorene]/(9,9-di-n-octylfluorene) copolymers
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
Temperature dependent spectroscopy of poly[9,9-bis-(2-ethyl)hexylfluorene]/(9,9-di-n-octylfluorene) copolymers
چکیده انگلیسی
A series of random polyfluorene (PF8) copolymers composed of linear di-n-octyl (F8) and branched bis(2-ethylhexyl) (F2/6) units has been synthesized and characterized by temperature dependent steady-state absorption and emission spectroscopy. The F2/6 polymer is already well known for forming conformationally disordered fivefold helices while the F8 polyfluorene adopts a number of distinct near-planar type conformational isomers. One of these conformational sequences is an unusual low-energy absorption and emission band known as the β phase. In these copolymers the PF chains must temporize between differing interchain packing motifs, pentagonal and planar type structures, and different main chain morphologies. Increasing the content of F2/6 monomers strongly affects the formation of the β phase conformer, enhances the extent of conformational disorder (and the effective electron-phonon coupling strengths) and also alters the bulk structural phase behavior. There are only weak correlations between the overall phase behavior and the observed spectroscopy at temperatures below 100 °C.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Luminescence - Volumes 122–123, January–April 2007, Pages 212-217
نویسندگان
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