- Layered morphology of poly(phenylene)s in thin films induced by substitution of well-defined poly(ε-caprolactone) side chains
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Poly(ε-caprolactone) (PCL)-based macromonomers and the corresponding substituted polyphenylene polymers have been synthesized in various chemical structures. The effect of chemical structure and the crystallization of PCL on the resulting morphology in thin films have been investigated. PCL macromonomers containing the central 2,5-dibromo-1,4-phenylene moiety were synthesized by ring-opening polymerization (ROP). Poly(phenylene) polymers were then synthesized by cross-coupling of the PCL macromonomers in Yamamato polycondensation reactions. Thin films of macromonomers and polymers were prepared by spin-coating on silicon substrates, and the resulting morphology in thin films was characterized by atomic force microscopy (AFM). Substitution of semicrystalline PCL side chains to the rigid poly(phenylene) backbone induced layered morphology in thin films. Our results indicate that increasing backbone rigidity causes grafted PCL side blocks to crystallize in better-defined layered structures parallel to the underlying substrate. Such layering was not observed when polystyrene (PSt) or poly(2-methyloxazoline) (POx) polymers were grafted to the rigid poly(phenylene) backbone. Hindering PCL crystallization by attaching PSt or POx to the end of PCL also prevented the formation of layered structures.
- Demirel, A. Levent,Yurteri, Seda,Cianga, Ioan,Yagci, Yusuf
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- Synthesis of oligophenylenevinylene heptamers substituted with fullerene moieties
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Oligophenylenevinylene (OPV) derivatives substituted with one or two fullerene subunits have been prepared starting from a fullerene carboxylic acid derivative and OPV heptamers bearing one or two alcohol functions. The electrochemical properties of the resulting C60-OPV derivatives have been investigated by cyclic voltammetry. Whereas the fist reduction of both C60-OPV conjugates is centered on the C60 unit, the oxidation is centered on the OPV rod. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Gegout, Aline,Holler, Michel,Figueira-Duarte, Teresa M.,Nierengarten, Jean-Francois
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experimental part
p. 3627 - 3634
(2009/04/07)
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- Synthesis and excited-state properties of an oligophenylenevinylene heptamer substituted with two fullerene moieties
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An oligophenylenevinylene (OPV) derivative substituted with two fullerene subunits has been prepared starting from a fullerene carboxylic acid derivative and an OPV heptamer bearing two alcohol functions. Photophysical investigations have revealed the occurrence of intramolecular photoinduced energy- and electron-transfer processes in this hybrid compound. Georg Thieme Verlag Stuttgart.
- Gégout, Aline,Figueira-Duarte, Teresa M.,Nierengarten, Jean-Fran?ois,Listorti, Andrea,Armaroli, Nicola
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p. 3095 - 3099
(2008/02/13)
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- Synthesis, characterization, and fluorescence quenching of novel cationic phenyl-substituted poly(p-phenylenevinylene)s
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Three new phenyl-substituted poly(p-phenylenevinylene) (Ph-PPV) derivatives with amino-functionalized groups were synthesized through either Gilch reaction for poly{2,5-bis[4′-2-(N,N-diethylamino)ethoxyphenyl]-1,4-phenylenevinylene (P1) or Wittig reaction for poly{2,5-bis(4′-decyloxyphenyl)-1,4-phenylenevinylene-alt-2,5-bis[4′ -2-(N,N-diethylamino)ethoxyphenyl]-1,4-phenylenevinylene} (P2) and poly(2,5-bis{4′-2-[2-(2-methoxyethoxy)ethoxy]ethoxyphenyl}-1,4-phenylenevi nylene-alt-2,5-bis[4′-2-(N,N-diethylamino)ethoxyphenyl]-1,4- phenylenevinylene) (P3). Green light-emitting cationic polymers, poly{2,5-bis(4′-decyloxyphenyl)-1,4-phenylenevinylene-alt-2,5-bis[4′ -2-(N,N,N-triethylammonium)ethoxyphenyl]-1,4-phenylenevinylene} dibromide (P2′) and poly(2,5-bis{4′-2-[2-(2-methoxyethoxy)ethoxy]ethoxyphenyl}-1,4-phenylenevi nylene-alt-2,5-bis[4′-2-(N,N,N-triethylammonium)ethoxyphenyl]-1, 4-phenylenevinylene) dibromide (P3′), were prepared from the neutral polymers P2 and P3, respectively. Water solubility was achieved on P3′ through increase of the hydrophilicity of the side chains. The acid-assistant reversible solubility of P1 makes it promising in preparing light-emitting multilayer devices. On the basis of FT-IR and 1H NMR spectra, it was found that P1 is primarily of trans-vinyl while P2 and P3 are of 80% and 81% cis-vinyl, respectively, which depends on the polymerization method employed. The bulky phenyl substituents successfully impeded the interchain interaction which led to quantum efficiency as films comparable to that of solutions. Quaternization also resulted in more twisted conformation of the polymer main chain which was supported by both blue-shifted absorption and reduced quantum efficiency of P2′ and P3′ in solutions and as films than that of the neutral polymers. The fluorescence of P3′ was efficiently quenched by an anionic quencher Fe(CN)64-, Ksv of which is 3.3 × 106 M-1. However, a modified Stern-Volmer plot showed that 9% of the fluophores could not be accessible to the quencher, which may result from the twisted conformation or intermolecular aggregation.
- Fan, Qu-Li,Lu, Su,Lai, Yee-Hing,Hou, Xiao-Yuan,Huang, Wei
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p. 6976 - 6984
(2007/10/03)
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