Untersuchungen über Stilbene, XL. Konjugierte Stilbazole

Drefahl, Günther; Plötner, Gerhard; Buchner, Günther

doi:10.1002/cber.19610940720

Cited by 16 publications

(1 citation statement)

References 12 publications

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“…Compounds 1 , 3 , 4 , 6 , 8 , and Pd(PEt 3 ) 4 were prepared according to published procedures. ,,,− Reagents were purchased from Aldrich or Merck and used as received. Solvents were reagent grade (AR) from either Bio-Lab (Jerusalem, Israel), Merck (Darmstadt, Germany), or Baker Mallinckrodt (Phillipsburg, NJ).…”

Section: Methodsmentioning

confidence: 99%

Positive Constructs: Charges Localized on Surface-Confined Organometallic Oligomers

et al. 2009

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Assemblies with molecular-level organization based on organic chromophores and a bimetallic palladium complex are presented. A layer-by-layer strategy is employed by alternately coordinating vinylpyridine-terminated chromophores to the metal centers to form cationic oligomers. These new structures are formed from solution on quartz and silicon substrates functionalized with a covalently bound template layer. Twelve consecutive deposition steps result in structurally regular assemblies as demonstrated by linear increases in the ellipsometrically determined thickness and UV−vis optical absorption. The increase in thickness for each additional layer shows that the long-range order of the system is determined by the structure of the chromophores and by the square-planar geometry of the metal centers. Furthermore, the optical properties indicate that the conjugation length of the assembly component does not increase in the surface-bound oligomers with each additional deposition cycle. Structural communication is transferred via the system components, but they remain electronically isolated. This is supported by density functional theory (DFT) calculations.

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Section: Methodsmentioning

confidence: 99%

Positive Constructs: Charges Localized on Surface-Confined Organometallic Oligomers

et al. 2009

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The Wittig Reaction

Maercker

2011

Organic Reactions

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In 1953 Wittig and Geissler found that reaction of benzophenone with methylenetriphenylphosphorane gave 1,1‐diphenylethylene and triphenylphosphine oxide in almost quantitative yield; the phosphine had been prepared from triphenylmethylphosphonium bromide and phenyl lithium. The discovery led to the development of a new method for the synthesis of olefins, under the name Wittig reaction. One advantage of this new method is that the carbonyl group is replaced specifically by a carbon‐carbon double bond without the formation of isomeric olefins. In contrast, the older method of converting carbonyl compounds to olefins using the Grignard reaction usually give a mixture of isomeric olefins. Another advantage is the Wittig reaction is carried out under mild conditions. Discussions of modern techniques for the preparation of methylene phosphoranes are included in this review.

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Synthesis and properties of compounds related to stilbazole

Nethsinghe

Plesch

Hodge

1987

Angew. Makromol. Chem.

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We report attempts to create conjugated polymers consisting of alternating phenylene and heterocyclic rings separated by double bonds by means of condensations between terephthdaldehyde and dimethyl nitrogen bases. Because the products precipitated during their formation even at 180 "C in N-methyl-2-pyrrolidinone (NMP), only oligomers of up to ca. 30 rings (DP = 15) could be obtained; most of the adequately soluble products had DP between 4 and 8, and from these oligomers films on glass or quartz could be made. When the films were exposed to Iz, N q , or SbF,, most of them, initially very good insulators, showed an increase in electrical conductivity of up to 6 powers of 10; but the rapid reversal of this change when the reagent evaporated and the lack of any clear changes in the UV-vis spectrum of the films showed that most likely true "doping" had not occurred.Extensive syntheses with a variety of quaternised bases also failed to yield oligomers oxidisable by electron-acceptors.For reference purposes, especially for their spectra, a large number of pure "model" compounds of the distyrylpyridine and distyrylpyrazine type, and quaternised analogues of the former, were synthesised, many of them new compounds. These were also used as calibrants for a GPC column operating with NMP solutions.Several improvements were made in the synthetic techniques.ZUSAMMENFASSUNG: Diese Arbeit beschreibt Versuche, durch Kondensation von Terephthalaldehyd mit Dimethylstickstoffbasen konjugierte Polymere zu synthetisieren, die aus alternieren-* Present address: Institute of Polymer Technology, Loughborough University of

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Untersuchungen über Stilbene, XL. Konjugierte Stilbazole

Abstract: Die Darstellung von Stilbazolen auf verschiedenen Wegen wird beschrieben und das spektroskopische Verhalten dieser Verbindungen diskutiert.

Cited by 16 publications

References 12 publications

Positive Constructs: Charges Localized on Surface-Confined Organometallic Oligomers

Positive Constructs: Charges Localized on Surface-Confined Organometallic Oligomers

The Wittig Reaction

Synthesis and properties of compounds related to stilbazole

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