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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 44 (1997), S. 179-186 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Retention-boiling point correlation ; Trouton's rule ; Alkylbenzenes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A thermodynamic interpretation of the empirical correlation between retention and boiling point for alkylbenzenes in stationary phases of low and medium polarity has been found. The transfer of molecules between the liquid and mobile phases was assumed to be similar to, although not identical with, vaporization of any given pure liquid and characterized using the Trouton's rule. The two equations developed relate relative retentions to solute boiling point and two systems constants under a given set of conditions. The first equation was found to give a better description since it involves fewer assumptions and approximations. Validity of the model was confirmed by agreement between theoretical and experimental values for equation constants although the agreement becomes poorer as the stationary phase polarity increases. The relationships discussed are applicable to all congeneric solutes of low polarity in stationary phases of medium polarity.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 271-275 
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Decomposition of 1-phenylethyl-hydroperoxide has been studied in the presence of 2,6-di-tert-butyl-4-methyl-phenol inhibitor in ethylbenzene and chlorobenzene both in oxygen and nitrogen. The oxygen consumption and the inhibitor concentrations were measured against the initial inhibitor concentrations. Two methods were applied for the determination of the rate coefficients of the reaction: \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm HROOH + InH}\mathop {\hbox to 30pt{\rightarrowfill}}\limits^{k_1 } {\rm HRO}^{\rm .} + {\rm In}^{\rm .} + {\rm H}_{\rm 2} {\rm O} $$\end{document} Its value is about 3 × 10-4L × mol-1 × S-1, at 120°C. However, large experimental errors we deal with, the existence of a reaction yielding radicals, presumably an interaction between hydroperoxide and inhibitor molecules, can be established emphasizing the importance of measurements carried out with various initial concentrations of the inhibitor.
    Additional Material: 2 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 25 (1993), S. 249-263 
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Absolute rate constants for the addition of the 2-cyano-2-propyl radical to 26 alkenes CH2=CXY at 315 K were determined in solution by time-resolved electron-spin-resonance spectroscopy. They vary with the alkene substituents from 30 M-1 s-1 to 7′010 M-1 s-1. For styrene the temperature dependence is given by log k/M-1 s-1 = 7.7 - 26.1/Θ where Θ = 2.303 RT in kJ/mol. An analysis of the substituent effects in terms of polar and enthalpic factors reveals a dominant influence of the overall reaction enthalpy. © 1993 John Wiley & Sons, Inc.
    Additional Material: 8 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 25 (1993), S. 913-920 
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Absolute rate constants for the addition of the 2-hydroxy-2-propyl radical to 18 substituted alkenes (CH2 = CXY) were determined at (296 ± 1) K in 2-propanol by time-resolved electronspin-resonance spectroscopy. With alkene substitution the rate constants vary by more than 6 orders of magnitude. For 3,3-dimethyl-but-1-ene the temperature dependence is given by log k/M-1 · s-1 = 6.4 minus;; 19.1/Θ where Θ = 2.303 RT in kJ/mol-1. As shown by a good correlation with the alkene electron affinities, log k296/M-1 · s-1 = 6.46 + 1.71 · EA/eV (r = 0.930), 2-hydroxy-2-propyl is a very nucleophilic radical, and its addition rates are highly governed by polar effects. © 1993 John Wiley & Sons, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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