Mn. Khan et Z. Abdullah, Kinetics and mechanism of alkaline hydrolysis of 4-nitrophthalimide in theabsence and presence of cationic micelles, INT J CH K, 33(7), 2001, pp. 407-414
Pseudo-first-order rate constants (k(obs)) for alkaline hydrolysis of 4-nit
rophthalimide (NPTH) decreased by nearly 8- and 6-fold with the increase in
the total concentration of cetyltrimethyl-ammonium bromide ([CTABr](tau))
from 0 to 0.02 M at 0.01 and 0.05 M NaOH, respectively. These observations
are explained in terms of the pseudophase model and pseudophase ion-exchang
e model of micelle. The increase in the contents of CH3CN from 1 to 70% v/v
and CH3OH from 0 to 80% v/v in mixed aqueous solvents decreases k(obs) by
nearly 12- and 11-fold, respectively. The values of k(obs) increase by near
ly 27% with the increase in the ionic strength from 0.03 to 3.0 M. The mech
anism of alkaline hydrolysis of NPTH involves the reactions between HO- and
nonionized NPTH as well as between HO- and ionized NPTH. The micellar inhi
bition of the rate of alkaline hydrolysis of NPTH is attributed to medium p
olarity effect. (C) 2001 John Wiley & Sons, Inc.