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Synthesis and electro-optical properties of polyfluorene modified with randomly distributed electron-donor and rotaxane electron-acceptor structural units in the main chain

: Farcas, A.; Janietz, S.; Harabagiu, V.; Guegan, P.; Aubert, P.H.


Journal of polymer science. A, polymer chemistry 51 (2013), Nr.7, S.1672-1683
ISSN: 0360-6376
ISSN: 0887-624X
ISSN: 1099-0518
ISSN: 1096-990X
European Commission EC
Fraunhofer IAP ()

Polyfluorene PF center dot CD rotaxane copolymer, composed of randomly distributed 9,9-dioctylfluorene, methyltriphenylamine (electron-donating) and 9-dicyanomethylenefluorene complexed with -cyclodextrin (CD) (electron-accepting) structural units, has been synthesized by Suzuki cross-coupling reaction. The chemical structures were proved by FTIR and 1H NMR spectroscopy. The surface morphology, thermal, optical, electrochemical behavior, and adhesion characteristics of the obtained rotaxane copolymer have been investigated and compared with those of the nonrotaxane counterpart (PF). Relatively high fluorescence efficiency, almost identical normalized absorbance maximum in solution and solid-state of PF center dot CD rotaxane copolymer, and a more uniform and smoother surface with lower adhesion forces provides the role of CD encapsulation on the lower aggregation propensity. PF center dot CD and PF copolymers exhibit n- and p-doping processes and blue-light emission in the film state. The optical and electrochemical band gaps (Eg), as well as the highest occupied molecular orbital/lowest unoccupied molecular orbital positions in an energetic diagram indicate that both copolymers are promising blue-emitting electroluminescent materials.