KINETICS OF REACTIONS OF AROMATIC BORONIC ACIDS WITH HYDROGEN PEROXIDE, BROMINE AND IODINE
Abstract
The kinetic reaction between H2O2 and benzeneboronic acid was investigated. First-and second-order reactions were distinguishable. The rates of both reactions increased with pH but were generally independent of buffer concentration and buffer constituents. In moderately strong solutions of HC1O4 and H2SO4 a reaction of first order in each reactant is observed; its rate increases with acidity. Rates of reaction of 13 meta-and para-substituted benzeneboronic acids with H2O2 in in 25% aqueous MeOH 1 M in HC1O4 were determined. The kinetics of the reaction between p-methoxybenzeneboronic acid and iodine was studied in 5% aqueous MeOH at 25.1 deg. C. The results demonstrate that molecular iodine attacks a p-methoxybenzeneboronate anion in the rate determining step. Studies on the kinetics and mechanism of the reaction between aromatic boronic acids and Br were continued. Attempts to prepare m- iodobenzeneboronic acid were unsuccessful. Known boronic acids with the following substituents were prepared: m - OCH3, m - Br, m - F, p - F and p - C6H5. Studies on the kinetics of the reaction of m-chlorobenzeneboronic acid in aqueous solution were initiated. Results indicate second-order kinetics and reciprocal dependence of rate on bromide ion concentration; molecular Br appears to be the brominating agent.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 15, 1953
- Accession Number
- AD0014188
Entities
People
- E. J. Soboczenski
- H. G. Kuivila
- L. E. Benjamin
- Rhonda M. Williams
Organizations
- University of New Hampshire