Kinetics of the reaction of phenyl picrates with phenoxide ions in water. Concerted or stepwise?†‡. (27th August 2013)

• Record Type: Journal Article
• Authors: Crampton, Michael R.; Robotham, Ian A.; Page, Michael I.
• Is Part Of: Journal of physical organic chemistry. Volume 26:Number 12(2013:Dec.)
• Page Start: 1084
• Page End: 1089
• Publication Date: 2013-08-27
• Subjects: Chemistry, Physical organic -- Periodicals; 547.1
• DOI: 10.1002/poc.3172
• Languages: English
• ISSNs: 0894-3230

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>A kinetic study is reported of the <named-content id="d339e880" content-type="reactionType" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">exchange reactions</named-content> of substituted phenoxide ions with some ring‐substituted 2, 4, 6‐trinitrophenyl ethers in water. The βrønsted diagrams formed by plotting log <italic>k</italic>, where <italic>k</italic> is the second‐order rate constant for reaction, versus p<italic>K</italic>_a show a distinct change in slope when Δp<italic>K</italic>_a = 0 (Δp<italic>K</italic>_a being the difference in p<italic>K</italic>_a values of the leaving group and nucleophile). This is consistent with a two‐step process involving a discrete σ‐adduct <named-content id="d339e910" content-type="reactionType" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">intermediate</named-content> rather than a concerted process. From the measured β values for forward and reverse processes, the overall effective charge map has been constructed. Copyright © 2013 John Wiley &amp; Sons, Ltd.</p> </abstract>