Temperature Dependence of Bromine Kinetic Isotope Effects for Reactions of n-Butyl and tert-Butyl Bromides

Article abstract of DOI:10.1021/ja00527a042

Techniques for the measurement of bromine leaving group kinetic isotope effects (KIE) are described.Experimental values at 20 deg C for the solvolysis of tert-butyl bromide (0.045M) in methanol with 0.3M 2,6-lutidine and for the reaction of n-butyl bromide (0.047M) with thiophenoxide anion (0.052M) in 0.025M lithium methoxide/methanol solvent are 1.00310 (+/-0.00004) and 1.00169 (+/-0.00003), respectively.The natural logarithm of the KIE was found to vary lineary with 1/T from 0 to 40 deg C for tert-butyl bromide, slope=0.472 (+/-0.080) deg^-1, and from -10 to 40 deg C for n-butyl bromide, slope=0.531 (+/-0.29) deg^-1.The significance of the KIE temperature dependencies is discussed.

Full text of DOI:10.1021/ja00527a042

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Evaluation Only. Created with Aspose.PDF. Copyright 2002-2021 Aspose Pty Ltd.