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  • 1
    Electronic Resource
    Electronic Resource
    Untersuchungen über Poly(arylenvinylen)e, 98. Mitt. s. Zit.1.. Zusammenhang zwischen der chemischen Struktur und der photoelektrischen Empfindlichkeit von Polyxylylidenen (1975)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 176 (1975), S. 691-698 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: In a series of differently substituted and isomeric poly(arylenevinylene)s (polyxylylidenes) it was found, that with the undoped polymers there is the relation (1) between the optical excitation energy Eopt and the photoelectrical sensitivity JPh. \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {J_{{\rm Ph}} = A(T)\exp - (0,34E_{{\rm opt}} /kT);} & {T = {\rm Const}{\rm .}} & {(1)} \\ \end{array}$$\end{document} This relation is discussed on the basis of a photochemical ionization of the macromolecules.
    Notes: An einer Reihe verschieden substituierter und isomerer Poly(arylenvinylen)e (Polyxylylidene) wurde gefunden, daß bei den undotierten Polymeren zwischen der optischen Anregungsenergie Eopt und der photoelektrischen Empfindlichkeit JPh der Zusammenhang (1) besteht. \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {J_{{\rm Ph}} = A(T)\exp - (0,34E_{{\rm opt}} /kT);} & {T = {\rm Const}{\rm .}} & {(1)} \\ \end{array}$$\end{document} Diese Beziehung wird auf der Grundlage einer photochemischen Ionisation der Makromoleküle diskutiert.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1975.021760312
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  • 2
    Electronic Resource
    Electronic Resource
    Untersuchungen über poly(arylenvinylen)e, 13.12. Mitt.: cf.1. Phenylsubstituierte poly-p-xylylidene. Durch UV-licht induzierte photoleitfähigkeit im NIR (1977)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 178 (1977), S. 195-202 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: UV-Irradiation of phenyl-substituted poly-p-xylylidenes induces photoconductivity in the range of 7000-17000 cm-1. The spectral distribution is identical with that of photoconductivity found in macromolecular radical cations produced chemically by oxidation with antimony pentachloride. This supports the assumption that the induced photoconductivity can be attributed to the photochemical generation (UV) and the optical excitation (VIS/NIR) of macromolecular radical ions.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1977.021780119
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  • 3
    Electronic Resource
    Electronic Resource
    Untersuchungen über Poly(arylenvinylene), 3029. Mitteilung: cf.1.. Synthese, Photoleitfähigkeit und Redox-Verhalten von Poly(9-methylcarbazol-3,6-diyl-1,2-diphenylvinylen) (1987)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 188 (1987), S. 2083-2104 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Soluble poly(9-methylcarbazole-3,6-diyl-1,2-diphenylvinylene) (1) Mn = 10000, was prepared by dehalogenating polycondensation of 3,6-bis(α,α-dichlorobenzyl)-9-methylcarbazole with chromium(II) acetate. The monomer was obtained from 3,6-dibenzoyl-9-methylcarbazole by reaction with PCl5. The chemical structure of 1 was verified by elemental analysis, UV, IR, and NMR spectroscopy, GPC, and VPO. 1 was found to be highly photoconducting, exhibiting a dark conductivity of 10-14 S/cm, which increases on doping with AsF5 to 10-4 S/cm. Its thermal stability under nitrogen is as high as with other phenylsubstituted poly(arylenevinylene)s (dec. temp.: 540°C; residue: 72 weight-%). The spectral distribution of sensitized (TNF, dyes) photoconductivity was studied and the redox behaviour was investigated by cyclovoltammetry. The redox potentials were found to be EOx1/2 = 0,90 V and ERed1/2 = -2,07 V (vs. Ag/AgCl). The electrochemical oxidation is reversible, associated with the formation of polydications derived from chain segments which consist of two carbazolediylvinylene units. Thus, 1,2-dicarbazole-3-yl-1,2-diphenylethylene as model compound well reflects the redox properties of the polymer. The electrochemical band gap energy was found to be 2,97 eV, which agrees closely with the energy of the optical absorption edge of 3,04 eV.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1987.021880907
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  • 4
    Electronic Resource
    Electronic Resource
    Thermogravimetrische untersuchung der dehydrohalogenierungspolymerisation von 4-methylphenyl-phenyldichlormethan. Untersuchungen über poly(arylenvinylene), 3130. Mitt. s. Lit1. (1986)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 142 (1986), S. 91-103 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: The formation of poly(1.4-phenylene-1-phenylvinylene) from 4-methylphenylphenyldichloromethane was investigated by means of the thermogravimetric analysis in a quasi-closed system.For the two-step mechanism of the HCl elimination the orders of reactions ni, the activation energies Ei and the rate constants Zi were estimated by modelling to n1 = 1.4, E1 = 105 kJ/mol, and Z1 = 108.9 s-1 for the first step, n2 = 1.3, E2 = 103 kJ/mol, and Z2 = 106.7 s-1 for the second step, respectively. In the first step of the reaction 77% of the total content of HCl were eliminated. The mechanism of the dehydrohalogenation polymerization is discussed.
    Notes: Die Bildung von Poly(1,4-phenylen-1-phenylvinylen) aus 4-Methylphenyl-phenyl-dichlormethan wurde thermogravimetrisch im quasi-geschlossenen System untersucht.Für den beobachteten zweistufigen HCl-Eliminierungsprozeß wurden durch Modellierung die Reaktionsordnungen ni, die Aktivierungsenergien Ei und die Geschwindigkeitskonstanten Zi zu n1 = 1,4; E1 = 105 kJ/mol und Z1 = 108,9 s-1 für die erste Stufe bzw. zu n2 = 1,3; E2 = 103 kJ/mol und Z2 = 106,7 s-1 für die zweite Stufe ermittelt. In der ersten Stufe wurden 77% des Gesamtgehaltes an HCl eliminiert. Der Mechanismus der Dehydrohalogenierungspolymerisation wird diskutiert.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1986.051420108
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  • 5
    Electronic Resource
    Electronic Resource
    Untersuchungen über Poly(arylenvinylen)e. XVII [1]. Poly(1,4-phenylen-1,2-diphenylvinylen) (1977)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 319 (1977), S. 611-621 
    Details
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Investigations on Poly (arylenevinylene)s. XVII. Poly(1,4-phenylene-1,2-diphenylvinylene)Soluble poly(1,4-phenylene-1,2-diphenylvinylene) of high molecular mass is synthesized by dehalogenation-polycondensation reaction of 1,4-bis(phenyldichloromethyl)benzene with water-free chromous acetate in a mixture of benzene/dimethylformamide. The absorption and photoconductivity spectra as well as a number of thermal (TGA, Tg) and electrical properties are described. Both the similarity of model reactions as the dehalogenation of diphenyldichloromethane to tetraphenylethylene and the dependence of the molecular mass on the quantity of the reducing agent lead to the conclusion that the above-mentioned polycondensation reaction takes place as a step-growth mechanism.
    Notes: Hochmolekulares, lösliches Poly(1,4-phenylen-1,2-diphenylvinylen) wird durch Dehalogenierungspolykondensation aus 1,4-Bis(phenyldichlormethyl)benzol mit wasserfreiem Chrom(II)-acetat in Benzol/Dimethylformamid synthetisiert. Es werden Absorptions- und Photoleitfähigkeitsspektren sowie einige thermische (TGA, Tg) und elektrische Eigenschaften mitgeteilt. An Hand von Modellreaktionen (Dehalogenierung zu Tetraphenyläthylen) und durch die Art der Abhängigkeit der Molmasse von der Menge des Reduktionsmittels wird auf einen Wachstumsprozeß nach einem Stufenmechanismus geschlossen.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19773190411
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  • 6
    Electronic Resource
    Electronic Resource
    Poly-p-xylyliden. Synthesen und beziehungen zwischen struktur und elektrophysikalischen eigenschaften (1970)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 131 (1970), S. 105-132 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Foly-p-xylylidene has been synthesized by bifunctional carbonyl olefination of terephthalaldehyde according to WITTIG'S reaction and by means of p-xylylene-bis-(diethyl phosphonate) as well as by dehydrochlorination of p-xylylene dichloride with sodium hydride in dimethyl formamide and with potassium amide in liquid ammonia. Then followed a comparative investigation of the products obtained. Methyl- and methoxy-substituted poly-p-xylylidenes II and III are obtained from 2.5-bis-(chloromethyl)-p-xylene and -hydroquinone dimethyl ether. I-III are being analyzed by IR and reflection spectra as well as by thermogravimetry. The poly-p-xylylidenes I-III possess semiconducting properties and photoconductivity, typical values for the dark conductivity and activation energy of I being σ400°K ∼ 10-15 ohm-1 cm-1 and ED = 2,4 eV.Absorption spectra and photoconductivity spectra occur in the same spectral region, photoconductivity on the long-wave edge of absorption possessing a maximum. The excitation energy for the photoconduction of I, E0 = 2,35 eV, is of the same value as ED and is approximately in accordance with the theoretically calculated value for the π-π* transition of the isolated macromolecule. Corresponding relations result from the substituted polyxylylidenes II and III.In order to characterize the conducting phenomena more closely measurements are being made concerning the dependence of the photocurrent and its relaxation time from voltage, temperature and radiation intensity. Also, the photoconductivity with combined optical excitation as well as the influence of oxygen on photoconduction are being examined.
    Notes: Poly-p-xylyliden (I) wird durch bifunktionelle Carbonylolefinierung von Terephthalaldehyd nach der WITTIGschen Reaktion und mit p-Xylylen-bis-[phosphonsäurediäthylester] sowie durch Dehydrochlorierung von p-Xylylendichlorid mit Natriumhydrid in Dimethylformamid und mit Kaliumamid in flüssigem Ammoniak hergestellt und vergleichend untersucht. Methyl- und methoxysubstituierte Poly-p-xylylidene (II) und (III) werden aus 2.5-Bis-[chlormethyl]-p-xylol und -hydrochinondimethyläther erhalten. I - III werden durch IR- und Reflexionsspektren und durch Thermogravimetrie analysiert. Die Polyxylylidene I - III besitzen Halbleitereigenschaften und Photoleitfähigkeit. Typische Werte für die Dunkelleitfähigkeit und Aktivierungsenergie von I sind σ400°K ≈ 10-15 Ohm-1 cm-1 und ED = 2,4 eV.Absorptions- und Leitfähigkeitsspektren fallen in den gleichen Spektralbereich, wobei die Photoleitfähigkeit an der langwelligen Kante der Absorption ein Maximum besitzt. Die Anregungsenergie für die Grenze der Photoleitung von I, E0 = 2,35 eV, besitzt dieselbe Größe wie ED und ist annähernd in Übereinstimmung mit dem theoretisch berechneten Wert für den π-π*-Übergang des isolierten Makromoleküls. Bei den substituierten Polyxylylidenen II und III ergeben sich entsprechende Beziehungen.Ferner wird zur näheren Charakterisierung der Leitungsphänomene die Abhängigkeit des Photostromes und dessen Relaxationszeit von der Spannung, der Temperatur und der Bestrahlungsstärke gemessen sowie die Photoleitfähigkeit bei kombinierter optischer Anregung und der Einfluß von Sauerstoff auf die Photoleitung untersucht.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1970.021310109
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