Schwalm, Thorsten ; Wiesecke, Jens ; Immel, Stefan ; Rehahn, Matthias (2009)
The Gilch Synthesis of Poly(p-phenylene vinylenes): Mechanistic Knowledge in the Service of Advanced Materials.
In: Macromolecular Rapid Communications, 30 (15)
doi: 10.1002/marc.200900104
Artikel, Bibliographie
Kurzbeschreibung (Abstract)
A consistent picture is presented of the mechanistic details and intermediates of the Gilch polymerization leading to poly(p-phenylene vinylenes) (PPVs). In-situ generated p-quinodimethanes are shown to be the real monomers, and spontaneous formation of the initiating radicals is effected by dimerization of some of these monomers to dimer diradicals, the latter also being the reason why significant amounts of [2.2]paracyclophanes are formed as side-products. Chain propagation predominantly proceeds by radical chain growth, occasionally interrupted by polyrecombination events between the growing α,ω-macro-diradicals. Based on this knowledge, oxygen is identified as a very efficient molar-mass regulating agent, and the temporary gelation of the reaction mixtures is interpreted to be the consequence of a very high entanglement of the polymers immediately after their formation. Last but not least, it is rationalized why the usually considered constitutional defects in Gilch PPVs might not be the only and most relevant ones with respect to the efficiency and durability of the organic light emitting devices produced thereof, and why cis-configurated halide-bearing vinylene moieties should be perceived as being among the most critical candidates. These considerations result in the recommendation of straightforward measures that should lead to clearly improved PPVs.
Typ des Eintrags: | Artikel |
---|---|
Erschienen: | 2009 |
Autor(en): | Schwalm, Thorsten ; Wiesecke, Jens ; Immel, Stefan ; Rehahn, Matthias |
Art des Eintrags: | Bibliographie |
Titel: | The Gilch Synthesis of Poly(p-phenylene vinylenes): Mechanistic Knowledge in the Service of Advanced Materials |
Sprache: | Englisch |
Publikationsjahr: | August 2009 |
Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Macromolecular Rapid Communications |
Jahrgang/Volume einer Zeitschrift: | 30 |
(Heft-)Nummer: | 15 |
DOI: | 10.1002/marc.200900104 |
Kurzbeschreibung (Abstract): | A consistent picture is presented of the mechanistic details and intermediates of the Gilch polymerization leading to poly(p-phenylene vinylenes) (PPVs). In-situ generated p-quinodimethanes are shown to be the real monomers, and spontaneous formation of the initiating radicals is effected by dimerization of some of these monomers to dimer diradicals, the latter also being the reason why significant amounts of [2.2]paracyclophanes are formed as side-products. Chain propagation predominantly proceeds by radical chain growth, occasionally interrupted by polyrecombination events between the growing α,ω-macro-diradicals. Based on this knowledge, oxygen is identified as a very efficient molar-mass regulating agent, and the temporary gelation of the reaction mixtures is interpreted to be the consequence of a very high entanglement of the polymers immediately after their formation. Last but not least, it is rationalized why the usually considered constitutional defects in Gilch PPVs might not be the only and most relevant ones with respect to the efficiency and durability of the organic light emitting devices produced thereof, and why cis-configurated halide-bearing vinylene moieties should be perceived as being among the most critical candidates. These considerations result in the recommendation of straightforward measures that should lead to clearly improved PPVs. |
Freie Schlagworte: | conjugated polymers; Gilch synthesis; mechanism elucidation; polymerization (general); poly(p-phenylene vinylenes) |
Zusätzliche Informationen: | SFB 595 A5 |
Fachbereich(e)/-gebiet(e): | DFG-Sonderforschungsbereiche (inkl. Transregio) > Sonderforschungsbereiche > SFB 595: Elektrische Ermüdung > A - Synthese > Teilprojekt A5: Synthese halbleitender Modellpolymere und deren Charakterisierung vor und nach zyklischer elektrischer Ermüdung DFG-Sonderforschungsbereiche (inkl. Transregio) > Sonderforschungsbereiche > SFB 595: Elektrische Ermüdung > A - Synthese DFG-Sonderforschungsbereiche (inkl. Transregio) > Sonderforschungsbereiche > SFB 595: Elektrische Ermüdung Zentrale Einrichtungen DFG-Sonderforschungsbereiche (inkl. Transregio) > Sonderforschungsbereiche DFG-Sonderforschungsbereiche (inkl. Transregio) |
Hinterlegungsdatum: | 04 Aug 2011 14:36 |
Letzte Änderung: | 05 Mär 2013 09:51 |
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