Diblock and random Donor/Acceptor "Double Cable" polythiophene copolymers via the GRIM method

F. Ouhib , Abdel Khoukh (1) , Jean-Bernard Ledeuil (1) , Hervé Martinez (1) , Jacques Desbrieres (1) , Christine Lartigau-Dagron (1)

1 IPREM - Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux

In this paper, we report the synthesis via the Grignard metathesis method (GRIM) of donor/ acceptor double cable copolymers with diblock and random sequences, where the conjugated polythiophene backbone is substituted with hexyl chains and with alkyl chains bearing fullerene. First, the monomers 2,5-dibromo-3-hexylthiophene and 2,5-dibromo-3-(l,3-dioxa-2-octyl)thiophene were randomly copolymerized and yielded after the grafting of fullerene C 60 the double cable CoPTR-C. Second, the same monomers were used to synthesize a diblock copolymer with a block made from a random copolymerization of both monomers while the second block is pure poly(3-hexylthiophene). After the grafting of fullerene, the block double cable CoPTBl-C was obtained. Both double cable copolymers were investigated through various characterization methods. NMR ID and 2D experiments allowed the full structural characterization and the determination of the final composition of the copolymers. The thermal behavior was investigated by TGA and DSC measurements, indicating that the incorporation of fullerene increased the thermal stability of the materials. The optical properties of these double cable copolymers were investigated by UV-visible absorption and fluorescence spectroscopy. The results showed no interaction at ground-state between the donor and acceptor moieties and a quenching of fluorescence of the polythiophene main chains in solution. AFM analysis on drop-casted films showed the dependence of the morphology of the double cable systems (random or diblock) on the aggregation. © 2008 American Chemical Society.

Mots clés: Absorption spectroscopy; AFM; Alkyl chains; Block copolymers; Cables; Cable systems; Carrier mobility; Characterization methods; Copolymerization; Diblock; Diblock copolymers; Donor and acceptors; Fluorescence; Fullerene c; Fullerenes; Grafting (chemical); Grignard metathesis methods; Ground-state; Main chains; Monomers; Optical properties; Organic polymers; Plastic products; Poly (3-hexylthiophene); Polymers; Polythiophene; Polythiophene copolymers; Quenching; Random copolymerizations; Random sequences; Structural characterizations; Synthesis (chemical); TGA and DSC; Thermal behaviors; Thermal stabilities; Thermodynamic stability; Thiophene; UV-visible absorptions

Domaines: Chimie; Matériaux

F. Ouhib, Abdel Khoukh, Jean-Bernard Ledeuil, Hervé Martinez, Jacques Desbrieres, et al.. Diblock and random Donor/Acceptor "Double Cable" polythiophene copolymers via the GRIM method. Macromolecules, 2008, 41 (24), pp.9736--9743. ⟨10.1021/ma801934g⟩. ⟨hal-01504349⟩