Effect of micellization on rate of cupric-ion-promoted hydrolysis of dicarboxylic acid hemiesters

✍ Scribed by John T. H. Ong; H. B. Kostenbauder

• Publisher: John Wiley and Sons
• Year: 1976
• Tongue: English
• Weight: 633 KB
• Volume: 65
• Category: Article
• ISSN: 0022-3549
• DOI: 10.1002/jps.2600651206

✦ Synopsis

The effect of micellar sodium lauryl sulfate on the rate of cupric-ion-promoted hydrolysis of some dicarboxylic acid hemiesters was investigated at pH 5, ionic strength 0.1 M, and 40, 45, and 50 degrees. The rate of cupric-ion-promoted hydrolysis of sodium n-decyloxalate in the micellar phase is about 50 times as fast as that in the bulk solution. The formation constant of the intermediate chelate complex, cupric decyl oxalate, was decreased in the micellar phase, while the rate of attack of hydroxide ion upon the chelate complex was increased. The overall rate increase is attributed to the increase in the entropy of activation for the reaction in the micellar phase. The rates of hydrolysis of sodium hydrocortisone 21-hemisuccinate and sodium hydrocortisone 21-hemi-(3,3-dimethylglutarate) were unaffected by copper ion.