Übergangsmetall‐katalysierte kondensations‐ und polykondensationsreaktionen

Heitz, Walter

doi:10.1002/apmc.1994.052230110

“…Usually, such findings indicate non-fluorescent impurities. With the bipyridyl-containing polymers various reaction side-products are conceivable, 26 some of which absorb at longer wavelengths: complexes with traces of metals, oxidation products, protonated bipyridyls and radicals. Metal complexes of bipyridylethinylenes have been described.…”

Section: Alkoxy-substituted Linear Models Oligomers and Polymersmentioning

confidence: 99%

Conjugated polymers with 2,2?-bipyridine and diethinylenebenzene units: absorption and luminescence properties

Grummt

¹

,

Birckner

²

,

Klemm

³

et al. 2000

J. Phys. Org. Chem.

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Alternating oligomers and polymers consisting of 2,2'-bipyridine and diethinylenebenzene units and corresponding model compounds were synthesized and investigated in dilute solutions by absorption spectroscopy and by stationary and time-resolved emission spectroscopy. The strictly linear (rod-like) p-chain oligomers/polymers were compared with the angularly linked oligomers/polymers and with related model compounds. The model compounds which already show the essential spectroscopic properties of the oligomers/polymers consist of three (hetero)aromatics linearly connected by two diethenylene groups. These models exhibit fluorescence quantum yields close to unity and short fluorescence decay times around 1 ns. Fluorescence anisotropy and rotational relaxation times are consistent with the Stokes-Einstein equation and the Perrin equation. The absorption and emission spectra of the polymers and their radiative rate constants determined by fluorescence quantum yield and lifetime and according to the Strickler/Berg equation show a conjugation length of one to two repetition units. The conjugation along the chain is stronger in linear than in angular polymers and stronger in alkoxy-substituted than in unsubstituted polymers. In angular polymers at least two different emitting segments were found. The shortened mean lifetimes and the reduced fluorescence quantum yields and anisotropies of the oligomers/polymers indicate an additional radiationless deactivation channel which is opened by energy migration along the chain. Rates of energy transfer calculated for linear and angular polymers correlate with rates of radiationless deactivation.

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“…Tail-end functionalized PPE can in principle be obtained by copolymerization. − When using (besides the DMP) a para -functionalized phenol, which can only partake in the redistribution reactions, this phenol will always end up as the tail-end of PPE. , However, rapid oxidative coupling will usually lead to large amounts of nonfunctionalized PPE as well. Furthermore, if one wants to use the commercially easily available ortho -unsubstituted phenols, extensive cross-linking , and methyl group oxidation , will occur.…”

Section: Introductionmentioning

confidence: 99%

Modified Poly(2,6-dimethyl-1,4-phenylene ether)s Prepared by Redistribution

Aert

¹

,

Genderen

²

,

Steenpaal

³

et al. 1997

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DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:

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“…Figure3. SEC star-shaped polymers prepared from different generations of dendrimer with the same estimated average arm length(22.5 units) using THF as eluents.…”

mentioning

confidence: 99%

Functional Oligomers, Telechelics, and Graft and Star-Shaped Poly(2,6-dimethyl-1,4-phenylene ether)s Prepared by Redistribution

Aert¹,

Burkard²,

Jansen³

et al. 1995

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DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:

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Übergangsmetall‐katalysierte kondensations‐ und polykondensationsreaktionen

Cited by 12 publications

References 27 publications

Conjugated polymers with 2,2?-bipyridine and diethinylenebenzene units: absorption and luminescence properties

Conjugated polymers with 2,2?-bipyridine and diethinylenebenzene units: absorption and luminescence properties

Modified Poly(2,6-dimethyl-1,4-phenylene ether)s Prepared by Redistribution

Functional Oligomers, Telechelics, and Graft and Star-Shaped Poly(2,6-dimethyl-1,4-phenylene ether)s Prepared by Redistribution

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