• Lifetimes ofα-halo andα-azidobenzyl carbocations in aqueous solution

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      https://www.ias.ac.in/article/fulltext/jcsc/114/01/0047-0054

    • Keywords

       

      Solvolysis; lifetimes; α-halobenzyl carbocations; α-azidobenzyl carbocations

    • Abstract

       

      The title cations were produced in aqueous solution by chemical initiation (solvolysis) of benzyl-gem-dihalides and benzyl-gem-diazides. The solvolysis reactions of benzyl-gem-dihalides and benzyl-gem-diazides in water proceed by a stepwise mechanism through α-halobenzyl carbocation and α-azidobenzyl carbocation intermediates, which are captured by water to give the corresponding carbonyl compounds as the sole detectable products. Rate constant ratiokx/ks(M−1) for partitioning of the carbocation between reaction with halide/azide ion and reaction with water is determined by analysis of halide/azide common ion inhibition of the solvolysis reaction. The rate constantsks(s-1) for the reaction of the cation with solvent water were determined from the experimental values ofkx/ks andksolv, for the solvolysis of the benzyl-gem-dihalides and benzyl-gem-diazides respectively, usingkx = 5 × 109M−1 s−1 for diffusion-limited reaction of halide/azide ion with α-substituted benzyl carbocations. The values of 1/ks are thus the lifetimes of the α-halobenzyl carbocations and α-azidobenzyl carbocations respectively.

    • Author Affiliations

       

      R Sanjeev1 V Jagannadham1

      1. Department of Chemistry, Osmania University, Hyderabad - 500 007, India
    • Dates

       
  • Journal of Chemical Sciences | News

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