Kinetics of the alkaline hydrolysis of fenuron in aqueous and micellar media

Article abstract of DOI:10.1002/kin.20279

The kinetics of the hydrolysis of fenuron in sodium hydroxide has been investigated spectrometrically in an aqueous medium and in cationic micelles of cetyltrimethylammonium bromide (CTAB) medium. The reaction follows first-order kinetics with respect to [fenuron] in both the aqueous and micellar media. The rate of hydrolysis increases with the increase in [NaOH] in the lower concentration range but shows a leveling behavior at higher concentrations. The reaction followed the rate equation, 1/k_obs = 1/k + 1/(kK|OH ^-]), where k_obs is the observed rate constant, k is rate constant in aqueous medium, and K is the equilibrium constant for the formation of hydroxide addition product. The cationic CTAB micelles enhanced the rate of hydrolytic reaction. In both aqueous and micellar pseudophases, the hydrolysis of fenuron presumably occurs via an addition-elimination mechanism in which an intermediate hydroxide addition complex is formed. The added salts decrease the rate of reaction.

Full text of DOI:10.1002/kin.20279

Kinetics of the Alkaline
Hydrolysis of Fenuron
in Aqueous and
Micellar Media
S. K. GANGWAR, M. Z. A. RAFIQUEE
Department of Applied Chemistry, Z. H. College of Engineering & Technology, Aligarh Muslim University,
Aligarh 202 002, India
Received 12 February 2007; revised 25 April 2007, 12 July 2007; accepted 15 July 2007
DOI 10.1002/kin.20279
Published online in Wiley InterScience (www.interscience.wiley.com).
ABSTRACT: The kinetics of the hydrolysis of fenuron in sodium hydroxide has been investigated
spectrometrically in an aqueous medium and in cationic micelles of cetyltrimethylammonium
bromide (CTAB) medium. The reaction follows first-order kinetics with respect to [fenuron] in
both the aqueous and micellar media. The rate of hydrolysis increases with the increase in
[
NaOH] in the lower concentration range but shows a leveling behavior at higher concentra-
−
tions. The reaction followed the rate equation, 1/kobs = 1/k + 1/(kK [O H ]), where k
is
obs
the observed rate constant, k is rate constant in aqueous medium, and K is the equilibrium
constant for the formation of hydroxide addition product. The cationic CTAB micelles enhanced
the rate of hydrolytic reaction. In both aqueous and micellar pseudophases, the hydrolysis of
fenuron presumably occurs via an addition–elimination mechanism in which an intermediate
hydroxide addition complex is formed. The added salts decrease the rate of reaction. ꢀC 2007
Wiley Periodicals, Inc. Int J Chem Kinet 39: 638–644, 2007
INTRODUCTION
hydrolysis of phenylureas pesticides proceeds through
an addition–elimination mechanism in both acidic and
basic media.
Phenylureas are widely used in agriculture as active
principles of efficient herbicides. They are absorbed
by roots and leaves with translocation and act as pho-
tosynthetic electron transport inhibitors upon the pho-
tosystem II [1]. Fenuron is widely used for the control
of woody plants and perennials plants [2]. It can be
used either pre- or post-emergent and is systemic.
The mechanisms of hydrolysis of phenylureas,
carboxylic acid, esters, and amide have been sub-
ject of investigation by many workers [3–12]. The
Surfactants are one of the important additives used
in formulations of pesticides and herbicides [13,14] to
(i) increase the solubility of the pesticide in aqueous
medium, (ii) stabilize the pesticide by controlling
evaporation or decomposition (above critical micelle
concentration (cmc)), (iii) enhance the effectiveness
of the pesticide by providing the fine spray, and
(iv) explore the mode of action of pesticide (hydrolysis
behavior) in biomacromolecular ensembles (e.g., en-
zymes). The surfactant also acts as a wetting, dispers-
ing, and emulsifying agent. Surfactants at air–water
interfaces and in water, or similarly strongly hydrogen-
bonded solvents, self-associate at concentrations above
Correspondence to: M. Z. A. Rafiquee; e-mail: drrafiquee@
gmail.com.
ꢀ
c 2007 Wiley Periodicals, Inc.

KINETICS OF ALKALINE HYDROLYSIS OF FENURON IN AQUEOUS AND MICELLAR MEDIA
639
the cmc to form association colloids known as micelles
15]. Aggregate effects of micelles on chemical reac-
Kinetic Measurement
[
The requisite amounts of surfactants, sodium hydrox-
ide, and methanolic solution of fenuron were taken
in a three-necked reaction vessel. The reaction ves-
sel was fitted with a double surface condenser to pre-
vent any evaporation. The reaction vessel was kept
in a thermostated water bath at the desired temper-
tivity are generally interpreted by using the pseudo-
phase model [16,17], which treats micelles and water
as separate reaction media, that is, as separate phase or
pseudophases. This approach has been successfully ap-
plied to a wide range of chemical reactions in micellar
solution [18–20]. Surfactant aggregates affect chemi-
cal reactivity primarily by binding or excluding reac-
tants and secondarily by changing the free energy of
activation.
◦
ature (± 0.1 C). The rate of reaction was monitored
by measuring absorbance in a water–methanol mix-
ture (9:1) and surfactants on an Elico SL-164 UV–vis
spectrophotometer using 1-cm-pathlength quartz cu-
vettes. All the kinetic experiments were run under the
first-order reaction condition in which the concentra-
The micellar pseudophase has been regarded as a
microenvironment having varying degrees of polarity,
water activity, and hydrophobicity with increasing dis-
tance from the interfacial region to its core. Micelle-
catalyzed reactions are considered as a model for
electrostatic and hydrophobic reactions in biological
systems [21] and provide information regarding the
mechanism of reaction occurring on biological sur-
faces because the micelle resembles enzymes struc-
turally and functionally. The study in CTAB micelles
will be helpful in understanding the mechanism of ac-
tion of herbicides in the biological process. The in-
−
tion of OH and surfactant was kept in large excess
over the fenuron concentration. During basic hydrol-
ysis of fenuron, the corresponding carbamate formed
has a slightly different value of λmax (248 nm). On
addition of few drops of acid, carbamate decomposes
immediately to give the spectrum of aniline. The ab-
sorbance was measured by taking 3-mL aliquots in
1
mL of 2 M sulfuric acid. The pseudo-first-order rate
constant was determined from the slope of in (A − Aα)
versus time, where A is the absorbance of fenuron at
λmax (239 nm). The reaction was followed up to 70% of
its completion (2 half-life periods). A nonlinear least-
square technique was used for the treatment of data
to obtain the value of KS and km. The best values,
which fit the curves, were obtained from the computer
program. The cmc of CTAB containing fenuron and
sodium hydroxide was determined conductometrically
−
fluence of temperature and concentrations of OH ,
CTAB, and fenuron on the rate of hydrolysis of fenuron
may be utilized in the determination of the fate of her-
bicides after its dispersal in the environment.
Keeping in view these reasons, the kinetic investi-
gation on the rate of hydrolysis of fenuron was carried
out under varying conditions of temperature and con-
centration of salts, sodium hydroxide, and cationic mi-
celles. The possible mechanism and the corresponding
rate equation are reported in this paper.
◦
−4
−3
.
at 80 C and its value was 8.2 × 10 mol dm
RESULTS AND DISCUSSION
EXPERIMENTAL
Materials
Reaction in the Aqueous Medium
The alkaline hydrolysis of fenuron was studied kinet-
ically in water–methanol solutions (9:1) under vary-
ing conditions of temperature and concentrations of
fenuron, surfactant, sodium hydroxide, and salts.
The order of the hydrolytic reaction with respect to
fenuron was investigated at different initial concentra-
Fenuron, 1,1-dimethyl-3-Phenylurea (Bharat Pesti-
cides Ltd., Mumbai, India), sodium hydroxide (97%;
Merck, Mumbai, India), sulfuric acid (99%; Merck,
Mumbai, India), methanol (99%; Merck, Mumbai,
India), cetyltrimethylammonium bromide (99.9%;
CDH, Mumbai, India), sodium chloride (99%; Quali-
gens, Mumbai, India) potassium nitrate (99%; CDH,
Mumbai, India) were used as received. All the other
chemicals used were of analytical reagent grade. Dou-
bly distilled and deionized water was used throughout
the experimental work.
−
5
tions of fenuron in the range of 4.0 × 10 to 1.0 ×
−
4
−3
−3
◦
10 mol dm in 0.1 mol dm NaOH at 80 C. The
calculated values of pseudo-first-order rate constants
were found to be independent of the initial concen-
trations of fenuron, thus confirming that the reaction
follows first-order kinetics in [fenuron]. A number of
kinetic experiments were carried out at fixed [fenuron]
Stock solutions of sodium hydroxide (1.0 mol
−
3
−5
−3
◦
dm ), cetyltrimethylammonium bromide (0.1 mol
(5.0 × 10 mol dm ) at 80 C in different concentra-
−3
−3
−2
−3
dm ), and sulfuric acid (2.0 mol dm ) were pre-
pared in distilled water. The stock solution of fenuron
tions of NaOH (1.0 × 10 to 1.0 mol dm ). The ob-
tained values of pseudo-first-order rate constants were
found to increase with the increase in [NaOH] linearly
2
−3
(
1.0 × 10− mol dm ) was prepared in methanol.
International Journal of Chemical Kinetics DOI 10.1002/kin

6
40
GANGWAR AND RAFIQUEE
Scheme 1
The reactivity of such a diamide group depends
upon the electron-donating or electron-withdrawing
nature of the groups attached to N-atoms. The
presence of the electron-donating methyl groups
in fenuron allows the hydroxyl ion (nucleophile)
to attack different basicity sites of the molecule
Figure 1 Effect of variation of k on [NaOH] in (
◦
) [aque-
ous] and ( ) [CTAB] media. Reaction conditions: [fenuron]
•
−
5
−3
−2
−3
)
(
5.0 × 10 mol dm ) and [CTAB] (1.0 × 10 mol dm
[22].
◦
at 80 C.
−
At lower basicity, OH attacks the carbonyl carbon
to form intermediate hydroxide ion addition complex.
Water acts as a general acid and protonates the inter-
mediate to facilitate the elimination of dimethyl amine
along with the formation of carbamate. Therefore,
the reaction proceeds through an addition–elimination
mechanism as presented in Scheme 1.
The attack by a water molecule on the tetrahedral
intermediate followed by the elimination of dimethyl
amine is the rate-determining step [7,8]. This results in
the formation of phenyl carbamate. The carbamate ion
is stable in basic medium [23,24].
at low basicity. At higher [NaOH], the values of the
rate constant remained almost constant (Fig. 1).
The activation energy and other thermodynamic pa-
rameters were calculated from the kinetic runs car-
ried out at fixed concentrations of NaOH (0.1 mol
−3
−5
−3
dm ) and fenuron (5.0 × 10 mol dm ) within the
◦
temperature range of 40–90 C. A straight line (with
2
r = 0.996) was obtained for the plot of log kobs ver-
sus 1/T . Arrhenius and Eyring equations were used
ꢁ
ꢁ=
to obtain the values of activation energy, ꢀH , ꢀS ,
Corresponding to Scheme 1, the rate equation is
give by
ꢁ=
and ꢀG , and these values are given in Table I.
Fenuron is an activephenylureaherbicideconsisting
of an aromatic ring and a ureic or diamide group in
which two methyl groups are attached to the N-atom.
Rate = kobs [fenuron]T
(1)
(2)
(3)
dp
Rate = dt = k[B]
−
=
kK[OH ][A]
where k is the rate constant and K is the equilibrium
constant for the formation of hydroxyl addition product
B. A is the initial concentration of fenuron.
Table I Values of Activation Parameters for the
Hydrolysis of Fenuron by Sodium Hydroxide in the
Absence and in the Presence of CTAB
The total fenuron concentration is given by
Activation
Parameters
In the Absence
of CTAB
In the Presence
of CTAB
[
A] = [A] + [B]
T
Ea (kJ mol 1)
−
51.8
49.3
223.5
48.3
45.8
235.2
−
=
[A] + K[OH ] [A]
#
−1
)
ꢀ
H (kJ mol
ꢀS (J K mol
−
#
−1
−1
= [A] (1 + K[OH ])
−
)
[
A]
Fenuron] = 5.0 × 10 mol dm , [NaOH] = 1 × 10−1 mol dm
−
5
−3
−3
T
[
[
,
or
[A] =
CTAB] = 1.0 × 10− mol dm
2
−3
.
1 + K[OH−]
International Journal of Chemical Kinetics DOI 10.1002/kin

KINETICS OF ALKALINE HYDROLYSIS OF FENURON IN AQUEOUS AND MICELLAR MEDIA
641
Scheme 2
ureas caused by deprotonation of the aryl-NH group as
presented in Scheme 2.
In this mechanism (Scheme 2) too, the rate-
determining step is elimination of dimethyl amine from
the anion of phenylurea to give phenyl isocyanate. The
phenyl isocyanate then reacts rapidly either with water
or at pH >8 with hydroxides ion to yield carbamate.
Thus, under various concentration ranges of NaOH,
the reaction proceeds through the formation of phenyl
carbamate (Schemes 1 and 2). In the alkaline medium
Figure 2 Plot of 1/rate constant (kobs and kψ ) versus
/[NaOH] for ( ) [aqueous] and ( ) [CTAB] media. Re-
action conditions: [Fenuron] (5.0 × 10 mol dm ) and
1
◦
•
−5
−3
−2
−3
◦
[
CTAB] (1.0 × 10 mol dm ) at 80 C.
On putting the value of [A] in terms of total fenuron
concentration, Eq. (3) becomes
(at pH >10), the carbamate is relatively long lived. In
−
the acidic and neutral media, the carbamate decarboxy-
lates rapidly to yield aniline [25]. With the increase in
basicity, the activity of water (which acts as a general
acid) decreases and, therefore, the rate of hydrolysis
becomes constant.
dP
dt
kK[OH ][A]T
=
(4)
(5)
−
1 + K[OH ]
kK[OH ]
+ K[OH−]
−
or
kobs =
1
by inverting Eq. (5), we get
Reaction in the Presence of Cationic
(CTAB) Micelles
1
1
1
= k
+
kK[OH ]
−
kobs
The influence of cationic micelles on the rate of hy-
drolysis of fenuron was studied under various concen-
Thus, a plot of 1/kobs versus 1/[NaOH] should give a
straight line. The observed results are plotted in Fig. 2,
which supports the mechanism presented in Scheme 1,
and the intercept and slope of the plot gave the values
of k and K. The values are given in Table II.
−4
trations of CTAB in the range from 5.0 × 10 mol
−3
−2
−3
◦
dm to 6.0 × 10 mol dm at a fixed NaOH concen-
−3
tration (0.1 mol dm ) at 80 C. The obtained values
of the pseudo-first-order rate constant, kψ , at different
surfactant concentrations are plotted in Fig. 3. The plot
shows a peaked behavior in CTAB micelles, in which
the maximum rate of hydrolysis is obtained at [CTAB]
In stronger basic media, the hydrolytic reaction is
initiated by the formation of conjugate base of phenyl-
−2
−3
(
1.0 × 10 mol dm ), and then the rate of hydrolysis
decreases on further increase in [CTAB].
Table II Values of k and K in the Aqueous and
The values of the pseudo-first-order rate constant
obtained in the presence of cationic ([CTAB] = 1.0 ×
◦
Presence of Micelles at 80 C
− −3
2
5
−1
)
K(mol dm3)
−1
10
mol dm ) micelles were found to be indepen-
Reaction Medium
10 k (s
dent of the initial concentrations of fenuron. The rate
of reaction was linearly dependent on [NaOH] initially,
but at higher [NaOH] the rate became independent of
[NaOH] (Fig. 1). Thus, a similar behavior of variation
Aqueous
CTAB
5.87
8.59
79.56
72.17
Fenuron] = 5.0 × 10− mol dm−3, [CTAB] = 1.0 × 10−2 mol dm−3
5
.
[
International Journal of Chemical Kinetics DOI 10.1002/kin

6
42
GANGWAR AND RAFIQUEE
Overall, the rate is expressed as
−
V = kψ [ST] = k[OH ][ST] = kw[Sw] + km[Sm]
T
where
[
ST] = [Sw] + [Sm]
−
−
−
m
[
OH ] = [OH ] + [OH ]
T
w
and
ꢂ
ꢂ
k + k Ks[Dn]
w
m
kψ =
(6)
1
+ Ks[Dn]
Figure 3 Effect of variation of kψ on [CTAB]. Reaction
ꢂ
−5
−3
The pseudo-first-order rate constants in aqueous (k )
conditions: [fenuron] (5.0 × 10 mol dm ) and [NaOH]
w
ꢂ
and micellar (k ) pseudophase are given by
m
−
3
◦
(
0.1 mol dm ) at 80 C.
ꢂ
−
w
k = kw[OH ]
(7)
(8)
−
w
of rate constants on [fenuron] and [NaOH] was ob-
served in the absence and presence of surfactants. A
straight-line plot (Fig. 2) for 1/kψ versus 1/[NaOH]
too suggests that the reaction followed the same mech-
anism in both the aqueous and micellar media. The ac-
tivation parameters were determined from the values
−
km[OH ]
ꢂ
m
k =
= kmmOH
m
Dn
where mOH is the mole ratio of micellar bound [OH ]
m
to micellar head group. km and kw are second-order
rate constants for reactions occurring in micellar and
aqueous pseudophases, respectively.
Equation (6) can now be expressed in terms of
second-order rate constants as
of kψ obtained at different temperatures in the range
◦
4
0–80 C. The concentrations of fenuron, NaOH, and
−5
−3
CTAB were kept constant at 5.0 × 10 mol dm , 0.1
−3
−2
−3
mol dm , and 1.0 × 10 mol dm , respectively. The
values of activation parameters are given in Table I.
The observed variation on the rate of hydrolysis
of fenuron in the micellar medium can be explained
by means of the pseudophase kinetic model proposed
by Menger and Portnoy [26] and later developed by
Bunton [16], Romsted [27,28], and Vera and Rodenas
−
kw[OH ] + (kmKs − kw)m
−
[Dn]
T
OH
kꢁ =
(9)
1
+ Ks[Dn]
For a reaction involving ions, Romsted [27] proposed
a theoretical method assuming that ions bind to mi-
celles, according to the ion exchange model developed
[29]. According to the pseudophase kinetic model, the
−
for an ion exchange resin. For the reactive OH ion
total volume of micelle is considered as a separate
phase uniformly distributed in the aqueous phase and
the reaction occurs in both the aqueous and micellar
phases.
−
and Br as the micelles counterion, the ion exchange
equilibrium can be expressed as [29]
−
K
OH/BR−
Scheme 3 is, therefore, proposed for the micellar-
catalyzed reaction, where S denotes fenuron, Dn the
micellized surfactant (Dn = [total surfactant] − cmc]),
and Ks the binding constant (Ks = [Sm]/[Sw][Dn]) of
fenuron with micelles. Subscripts “w” and “m” denote
aqueous and micellar pseudophases, respectively.
−
−
−
−
OH + Br ꢁꢀ OH + Br
(10)
w
m
m
w
with an equilibrium constant
− −
[OHm][Brw]
−
K
−
−
=
[OH ][Br ]
(11)
OH /Br
−
−
w
m
−
−
mOH in terms of K /Br is given by the following
OH
quadratic equation:
ꢀ
ꢁ
−
−
T
[
OH ] + K
−
−
[Br ]
2
OH
T
OH /Br
m
+ mOH
− (K
− β
(
K
−
−
− 1)[Dn]
= 0
OH /Br
−
β[OH ]
T
(12)
Scheme 3
−
−
− 1)[Dn]
OH /Br
International Journal of Chemical Kinetics DOI 10.1002/kin

KINETICS OF ALKALINE HYDROLYSIS OF FENURON IN AQUEOUS AND MICELLAR MEDIA
643
Table III Parameter Used to Simulate kψ − [CTAB]
Profile
Parameters
Values
−
1
3
Ks (mol dm )
220.00
(1.52 ± 0.24) × 10
0.80
−
1
3
−1
−4
km (mol dm s
)
β
−
K
−
6.00
8.20 × 10−4
OH /Br
cmc (mol dm 3)
−
Fenuron] = 5.0 × 10 mol dm−3, [NaOH] = 0.1 mol dm−3, and
−
5
[
◦
temperature = 80 C.
where β is the fraction of neutralized micellar surface
and its value for CTAB is 0.80 [11,29].
The reactants exist in dynamic equilibrium between
the aqueous and micellar pseudophases. The fitting
Figure 4 Effect of variation of kψ on [NaCl] and
[KNO ]. (ꢀfor KNO and for NaCl). Reaction condi-
values of km, K
−
−
, and KS were obtained from
OH /
Br−
3
3
•
the computer program by minimizing the deviation
between the simulation and the observed values for the
kψ − [CTAB] profile. The values of these parameters
are given in Table III.
−5
−3
tions: [fenuron] (5.0 × 10 mol dm ), [CTAB] (1.0 ×
−2 −3 −3 ◦
10
mol dm ] and [NaOH] (0.1 mol dm ) at 80 C.
Figure 4 shows the effect of added [NaCl] and
KNO3] on the rate of hydrolysis of fenuron by NaOH
The observed higher rate in CTAB could be at-
tributed to the binding of fenuron onto the posi-
tively charged micellar surface. The electron-rich car-
bonyl part of fenuron is oriented toward the positively
[
in the presence of CTAB micelles. The decreased rate
of reaction in the presence of CTAB by NaCl and KNO3
is attributed to the competitive binding of counterions
present with the micelles; therefore, the addition of
−
charged surface of CTAB micelles. The OH and re-
active part of fenuron lie in close proximity to the
micellar Stern layer. The other factors that influence
the rate of reaction involve the interaction of the polar
transition states with asymmetric charged interfacial
region, depletion of water in the interfacial region, and
its different characteristics as compared to bulk water
−
salt decreases the concentration of OH in the Stern
layer [30–32]. The inhibition is also due to the pres-
ence of salts, which increase the aggregation number
and reduce catalytic efficiency of the surfactant.
(
polarity of micelles is lower relative to bulk water), the
CONCLUSION
presence of high-ionic concentration in the Stern layer
of cationic micelles, the difference in the stabilization
of reactant state, and the transition state by hydropho-
The influence of NaOH, CTAB, and temperature on
the hydrolytic reaction of fenuron gave detailed infor-
mation about the reaction pathway. The rate equation
consistent with the mechanism of reaction is deduced.
The obtained result supports the proposed mechanism.
The cationic CTAB micelles enhanced the rate of reac-
tion, and the pseudophase ion exchange model is suc-
cessfully applied. The hydrolysis of fenuron proceeds
through the formation of isocyanate and dimethy-
lamine. The study will be helpful in understanding the
mechanism of action of herbicides in biological pro-
cesses as the surfactant aggregates mimic the enzymes
structurally and functionally. The study will also be
helpful in predicting the fate of herbicide after its dis-
persal in the environment
bic interactions with surfactant. With the increase in
−
[CTAB], the local molarities of fenuron and OH ions
in the micellar pseudophase increase and, therefore,
the enhancement in the rate of hydrolysis is observed.
Two distinct effects can be considered for the de-
crease in the rate of hydrolysis at higher CTAB con-
centrations. First, as the concentration of CTAB in-
−
creases, the number of the unreactive Br ions also
−
increases and replaces micelles-bound OH ions. The
−
displacement of OH from the vicinity of the Stern
layer causes a decrease in [OH ] in the micellar pseu-
−
dophase. Second, the increase in CTAB concentration
results in the formation of an increased number of mi-
−
celles and causes dilution of micellar-bound [OH ].
−
Thus, in both cases, the OH concentration in the mi-
cellar pseudophase is decreased. It results in the dilu-
−
tion of OH in the micellar pseudophase and, therefore,
The authors thank the Chairman, Applied Chemistry Depart-
ment, Z. H. College of Engineering and Technology, Aligarh
reduces the rate of reaction.
International Journal of Chemical Kinetics DOI 10.1002/kin

6
44
GANGWAR AND RAFIQUEE
Muslim University, Aligarh, U.P., India, for providing re-
search facilities and encouragement.
15. Tanford, C. The Hydrophobic Effect: Formation of Mi-
celles and Biological Membrane, 2nd ed.; Wiley: New
York, 1980.
1
1
1
6. Bunton, C. A.; Robinson, L. J Am Chem Soc 1968, 90,
972.
7. Cordes, E. H. (Ed.). Reaction Kinetics in Micelles;
Plenum Press: New York, 1973; p 73.
8. Bunton, C. A.; Nome, F.; Quina, F. H.; Romsted, L. S.
Acc Chem Res 1991, 24, 357.
5
BIBLIOGRAPHY
1. Khodja, A. A.; Boulkamh, A.; Boule, P. Photochem
Photobiol Sci 2004, 3, 145.
19. Bunton, C. A. In Kinetics and Catalysis in Microhetroge-
nous System; Gratezal, M.; Kalyansundaram, K. (Eds.);
Marcel Dekker: New York, 1991.
2. Hartly, D.; Kids, H. The Agrochemical Hand
Book; Royal Society of Chemistry: Nottingham, UK,
1
987.
20. Bunton, C. A.; Savelli, G. Adv Phys Org Chem 1986,
22, 213.
21. Bunton, C. A. J Molec Liq 1997, 72, 231.
22. Gora, A.; Toepfer, B.; Puddu, V.; Puma, G. L. Appl Catal
B: Environ 2006, 65, 1.
3
4
. Satchell, D. P. N.; Satchell, R. S. In The Chemistry of
Acid Derivatives; Patai, S. (Ed.); Wiley: Chichester, UK,
1
992; p. 747.
. Johnson, S. L. Adv Phys Org Chem 1967, 5,
37.
2
23. Hegarty, A. F.; Frost, L. N. J Chem Soc, Perkin Trans 2
1973, 1719.
5
6
. Bender, M. L. Chem Rev 1960, 60, 53.
. Jencks, M. P. Catalysis in Chemistry and Enzymology;
McGraw-Hill: New York, 1987; p. 467.
. Laudien, R.; Mitzner, R. J Chem Soc, Perkin Trans 2
24. Caplow, M. J Am Chem Soc 1968, 90, 6795.
25. Johnson, S. L.; Morrison, D. L. J Am Chem Soc 1972,
94, 1323.
26. Menger, F. M.; Portnoy, C. F. J Am Chem Soc 1967, 89,
4698.
27. Romsted, L. S. In Symposium on Surfactants in Solu-
tion, Lund, Sweden, 1982.
28. Romsted, L. S. In Micellization, Solubilization and Mi-
croemulsion; Mittal, K. L. (Ed.); Plenum Press: New
York, 1982; p. 569.
7
8
9
2
001, 2230.
. Laudien, R.; Mitzner, R. J Chem Soc, Perkin Trans 2
002, 2226.
2
. Salvestrini, S.; Di cerbo, P.; Capasso, S. J Chem Soc,
Perkin Trans 2 2002, 1889.
1
1
1
1
1
0. Giffeney, C. J.; O’Connor, C. J. J Chem Soc, Perkin
Trans 2 2001, 362.
1. Gangwar, S. K.; Rafiquee, M. Z. A. Int J Chem Kinet
29. Rodenas, E.; Vera, S. J Phys Chem 1983, 89, 513.
30. Spindli, D.; Noto, R.; Consiglo, G.; Werber, G.;
Buccheri, F. J Organelle Chem 1967, 43, 4042.
31. Broxton, T. R.; Deady, L. W.; Duddy, N. W. Aust J Chem
1978, 31, 1525.
2
007, 39, 39.
2. Gangwar, S. K.; Rafiquee, M. Z. A. Colloid Polym Sci
007, 285, 587.
3. Tonellato, U. J Chim Phys Phys-Chim Biol 2001, 85,
047.
4. Stevens, P. I. G. Pestic Sci 1993, 38, 103.
2
1
32. Ganmantel, N. G.; Page, M. I. J Chem Soc, Perkin Trans
2 1982, 1947.
International Journal of Chemical Kinetics DOI 10.1002/kin