title: Amphiphilic conjugated block copolymers: synthesis and solvent-selective photoluminescence quenching.
abstract: A novel, amphiphilic, conjugated block copolymer is described, which was prepared by a Suzuki-type cross-coupling of 2-bromo-[9,9-bis(2-ethylhexyl)fluorene]-7-pinacolato boronate as an AB-type monomer and monobromo-substituted poly[3-(6-bromohexyl)thiophene] (Br-P3BrHT) as a polymeric end capper in the key step. PF-P3PHT (P2; PF = poly(9,9-dialkylfluorene); P3PHT = poly[3-(6-diethylphosphonato-hexyl)thiophene]) as the amphiphilic target polymer was then generated in a polymer-analogous conversion of the alkyl bromide side chains of the PF-P3BrHT (P1) precursor into polar alkyl phosphonate groups by reaction with triethyl phosphite. P2 shows a strong influence of the solvent polarity on the optical spectra (absorption, emission). Treatment of solutions of P2 in tetrahydrofuran (THF), a nonselective solvent, with increasing amounts of solvents that are selective for the polar polythiophene blocks (water) or the nonpolar polyfluorene blocks (hexane), respectively, results in the formation of two different types of core-shell aggregates, which show rather different optical properties (photoluminescence quenching, excitation energy transfer).
authors: Makromolekulare Chemie and Institut für Polymertechnologie, Bergische Universität Wuppertal, Gauss-Strasse 20, 42097 Wuppertal, Germany. tu@uni-wuppertal.de
authors: Guoli
authors: G
authors: Tu
authors: Hongbo
authors: H
authors: Li
authors: Michael
authors: M
authors: Forster
authors: Ralf
authors: R
authors: Heiderhoff
authors: Ludwig J
authors: LJ
authors: Balk
authors: Reinhard
authors: R
authors: Sigel
authors: Ullrich
authors: U
authors: Scherf
mesh_terms: D005663:Furans / Q000737:chemistry; D006586:Hexanes / Q000737:chemistry; D049449:Luminescence; D018625:Microscopy, Atomic Force; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D014867:Water / Q000737:chemistry
chemical_list: D005663:Furans; D006586:Hexanes; D011108:Polymers; D012997:Solvents; D014867:Water; C026385:n-hexane; C018674:tetrahydrofuran