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  • 1
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Pyrazolo[1,5-a]pyridine undergoes fragmentation upon electron-impact by loss of HCN or C2H2N·. In the 2,3-dimethyl derivative loss of HCN and CH3CN were both observed from the [M - 1]+ ion and, in the 3-methyl-2-phenyl derivative, loss of PhCN occurred from the corresponding [M - 1]+ ion. Loss of methyl and phenyl radicals was also observed. In 3-acetyl-2-methyl and 3-benzoyl-2-phenyl derivatives, characteristic losses of the CH3CO· and PhCO· groups were noted. The introduction of a 7-methyl substituent into the six-membered ring had little effect on the fragmentation pattern.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 5 (1971), S. 1-13 
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The major decomposition pathway involved in the fragmentation of derivatives of the title ring systems was the loss of RCN from the five-membered ring, except when this ring had a 3-amino,3-hydroxyl or 3-mercapto substituent. In these cases, the exocyclic substituent and at least one nitrogen atom from the five-membered ring were lost.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 555-564 
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The mechanism of acid catalyzed decomposition of peroxodisulfate, (S2O82-) in aqueous perchlorate medium involves the hydrolysis of the species H2S2O8 and HS2O8- and the homolysis of the species H2S2O8, HS2O8- and S2O82- at the O—O bond. The overall rate law when 1.4M 〉 [HClO4] 〉 0.1M is \documentclass{article}\pagestyle{empty}\begin{document}$$ \frac{{ - d[{\rm S}_{\rm 2}{\rm O}_8^{2 - }]}}{{dt}}\, = \,k_0 [{\rm S}_{\rm 2}{\rm O}_8^{2 - }]\, + \,k' [{\rm S}_{\rm 2}{\rm O}_8^{2 - }][{\rm H}+]\, + \,k{''}[{\rm S}_{\rm 2}{\rm O}_8^{2 - }][{\rm H}+]^2 $$\end{document}The constants k′ and k″ contain the hydrolysis and homolysis rate constants of HS2O8- and H2S2O8, respectively. With added Ag(I), the acid catalyzed and Ag(I) catalyzed reactions take place independently. Ag(I) catalyzed decomposition appears to involve the species AgS2O8- (aq).
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 199-207 
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Results on the oxidation of N3- by Br2 in neutral and acid media are presented. The rate of the reaction is found to be proportional to [N3-] and [Br2]. The gaseous product of oxidation is found to be pure nitrogen. The stoichiometry of the reaction is \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm Br}_2 + 2{\rm N}_{\rm 3}^ - \to 2{\rm Br}^ - + 3{\rm N}_{\rm 2} {\rm ([N}_{\rm 3}^ -]) 〉 [{\rm Br}_2] $$\end{document} The reaction shows a positive salt effect. It is found that the addition of Br- stabilizes the complex BrN3, which decomposes into Br- and N2: \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {{\rm Br}_2 + {\rm N}_{\rm 3}^ - \rightleftharpoons {\rm BrN}_{\rm 3} + {\rm Br}^ - } \\ {{\rm BrN}_3 + {\rm N}_{\rm 3}^ - \to {\rm Br}^ - + 3{\rm N}_{\rm 2} } \\ \end{array} $$\end{document} The spectroscopic measurements also support the kinetic observation. The equilibrium constant K, the rate constants and the thermodynamic parameters were calculated. It is observed that H+ ion inhibits the reaction. The mechanism is discussed in terms of the kinetic results.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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