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Gasphasen-Reaktionen, 91 [1-3]<br />Thermische und heterogen-katalysierte N2-Abspaltung aus Azo-Verbindungen R–N=N–R (R = CH3, C3H5, C6H5) / Gas Phase Reactions, 91 [1-3]<br />Thermal and Heterogeneously Catalyzed N2 Elimination of Azo-Compounds R–N=N–R (R = CH3, C3H5, C6H5)

Gasphasen-Reaktionen, 91 [1-3]
Thermische und heterogen-katalysierte N2-Abspaltung aus... Thermal decompositions of azo compounds in the gas phase under reduced pressure are further investigated using photoelectron spectroscopic gas analysis. Passing diallyl, diphenyl and phenylmethyl derivatives either through a short-pathway pyrolysis (SPP) apparatus or through an external thermal reactor (ETR) results in the following fragmentations: Under nearly unimolecular conditions (SPP, 10-4 mbar pressure), diallyldiazene decomposes above 600 K to N2 and hexadiene-1,5 with the allyl radical as a detectable intermediate. The PE spectra recorded for diphenyldiazene above 1000 K (ETR, 1-2 mbar pressure) show N2, benzene, as well as traces of diphenyl. Phenylmethyldiazene yields above 800 K (SPP) predominantly N2, toluene, diphenyl and ethane with the methyl radical as the only detectable intermediate. Insertion of quartz wool into the pyrolysis tube (ETR) lowers the fragmentation temperatures, and in addition, above 850 K, HCN and aniline are PE spectroscopically identified. Surprisingly, this second reaction channel can be heterogeneously catalyzed: phenylmethyldiazene decomposes under 10-2 mbar pressure at a [Ni/SiO2] catalyst surface selectively to HCN and aniline. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Zeitschrift für Naturforschung B de Gruyter

Gasphasen-Reaktionen, 91 [1-3]<br />Thermische und heterogen-katalysierte N2-Abspaltung aus Azo-Verbindungen R–N=N–R (R = CH3, C3H5, C6H5) / Gas Phase Reactions, 91 [1-3]<br />Thermal and Heterogeneously Catalyzed N2 Elimination of Azo-Compounds R–N=N–R (R = CH3, C3H5, C6H5)

Bock, Hans; Berkner, Bodo
Zeitschrift für Naturforschung B , Volume 47 (11): 10 – Nov 1, 1992
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Publisher
de Gruyter
Copyright
© 1946 – 2014: Verlag der Zeitschrift für Naturforschung
ISSN
0932-0776
eISSN
1865-7117
DOI
10.1515/znb-1992-1108
Publisher site
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Abstract

Thermal decompositions of azo compounds in the gas phase under reduced pressure are further investigated using photoelectron spectroscopic gas analysis. Passing diallyl, diphenyl and phenylmethyl derivatives either through a short-pathway pyrolysis (SPP) apparatus or through an external thermal reactor (ETR) results in the following fragmentations: Under nearly unimolecular conditions (SPP, 10-4 mbar pressure), diallyldiazene decomposes above 600 K to N2 and hexadiene-1,5 with the allyl radical as a detectable intermediate. The PE spectra recorded for diphenyldiazene above 1000 K (ETR, 1-2 mbar pressure) show N2, benzene, as well as traces of diphenyl. Phenylmethyldiazene yields above 800 K (SPP) predominantly N2, toluene, diphenyl and ethane with the methyl radical as the only detectable intermediate. Insertion of quartz wool into the pyrolysis tube (ETR) lowers the fragmentation temperatures, and in addition, above 850 K, HCN and aniline are PE spectroscopically identified. Surprisingly, this second reaction channel can be heterogeneously catalyzed: phenylmethyldiazene decomposes under 10-2 mbar pressure at a [Ni/SiO2] catalyst surface selectively to HCN and aniline.

Journal

Zeitschrift für Naturforschung B – de Gruyter

Published: Nov 1, 1992

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