Oxidative degradation of D-sucrose by employing N-bromosuccinimide as oxidant: A micellar kinetic and catalytic study

Article abstract of DOI:10.1080/15533174.2012.680144

The oxidation of D-sucrose by N-bromosuccinimide and surfactants as a catalyst in the presence of acidic medium was studied at 45°C (± 0.1°C). The rate studies were made under pseudo-first-order conditions with an excess of sugar over the oxidant. In this

Full text of DOI:10.1080/15533174.2012.680144

This article was downloaded by: [University of Arizona]
On: 17 May 2013, At: 12:41
Publisher: Taylor & Francis
Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House,
37-41 Mortimer Street, London W1T 3JH, UK
Synthesis and Reactivity in Inorganic, Metal-Organic,
and Nano-Metal Chemistry
Publication details, including instructions for authors and subscription information:
http://www.tandfonline.com/loi/lsrt20
Oxidative Degradation of D-Sucrose by Employing N-
Bromosuccinimide as Oxidant: A Micellar Kinetic and
Catalytic Study
a
Minu Singh
a
Department of Chemistry, Kalyan Post Graduate College, Bhilai Nagar, Durg, Chhattisgarh,
India
Accepted author version posted online: 13 Jul 2012.Published online: 01 Oct 2012.
To cite this article: Minu Singh (2012): Oxidative Degradation of D-Sucrose by Employing N-Bromosuccinimide as Oxidant: A
Micellar Kinetic and Catalytic Study, Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry, 42:9,
1315-1326
To link to this article: http://dx.doi.org/10.1080/15533174.2012.680144
PLEASE SCROLL DOWN FOR ARTICLE
Full terms and conditions of use: http://www.tandfonline.com/page/terms-and-conditions
This article may be used for research, teaching, and private study purposes. Any substantial or systematic
reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to
anyone is expressly forbidden.
The publisher does not give any warranty express or implied or make any representation that the contents
will be complete or accurate or up to date. The accuracy of any instructions, formulae, and drug doses should
be independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims,
proceedings, demand, or costs or damages whatsoever or howsoever caused arising directly or indirectly in
connection with or arising out of the use of this material.

Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry, 42:1315–1326, 2012
Copyright ꢀC Taylor & Francis Group, LLC
ISSN: 1553-3174 print / 1553-3182 online
DOI: 10.1080/15533174.2012.680144
Oxidative Degradation of D-Sucrose by Employing
N-Bromosuccinimide as Oxidant: A Micellar Kinetic
and Catalytic Study
Minu Singh
Department of Chemistry, Kalyan Post Graduate College, Bhilai Nagar, Durg, Chhattisgarh, India
essential to know the velocity of the reaction.[1,2] A surfactant
The oxidation of D-sucrose by N-bromosuccinimide and surfac- is often quite useful in present supersensitive determination of
tants as a catalyst in the presence of acidic medium was studied
reaction rate due to its solubilization, stabilization, raising sensi-
tivity, and so on. Recently, the study of the surfactant molecular
aggregation is still very active. Understanding the aggregation of
◦
◦
at 45 C (± 0.1 C). The rate studies were made under pseudo-first-
order conditions with an excess of sugar over the oxidant. In this
aim was followed a mechanistic and structural investigation based
on a micellar kinetic study. The kinetics revealed first-order depen-
micelle and its assembly with small ions is verysignificant tocat-
dence on N-bromosuccinimide and fractional-order dependence on alyze the new-type efficient reactions.[ Organobromine com-
3–5]
D-sucrose. Variations of mercuric acetate had an insignificant effect
pounds do occur naturally, and some may be of use to higher or-
on reaction rate. The solvent effect revealed that negative dielectric
ganisms in dealing with parasites. N-bromosuccinimide (NBS)
effect. The influence of salts on the reaction rate was also studied.
Succinimide and sulfuric acid inhibit the rate. The rate constant
is the source of hypobromous acid (HOBr). In the body HOBr
was formed by the eosinophils in the presence of H2O2, and
(
k
W
), binding constants (K
S
+K
O
), and corresponding activation
#
#
#
parameters (E , ꢀH , ꢀS , and ꢀG ) were determined. A detailed eosinophil peroxidase provides a potent mechanism by which
a
mechanism with associated reaction kinetics is presented and dis-
cussed. Differences among the oxidation rates of the D-sucrose in
the presence of various surfactants discussed qualitatively in terms
of Berezin’s model, nature of surfactants, and charge of surfac-
tants.
eosinophils kill multicellular parasites, certain bacteria such as
[6–11]
tuberculosis bacteria.
The disaccharide, D-sucrose, consists
of one molecule of each of two monosaccharides—glucose and
fructose. Carbohydrate units are constituents of nucleic acids
and play an important role in metabolism and in mammalian
food supply.[
12–25]
D-sucrose is found in fruits and vegetables
Keywords Berezin’s model, critical micellar concentration, D-
sucrose, micellar kinetics, N-bromosuccinimide, oxida- and is particularly plentiful in sugar beets (roots) and sugarcane
tion
[26–31]
(
a grass).
Therefore, the oxidative degradation of sugars by different
INTRODUCTION
oxidizing agents has been the subject of numerous investigators
for long period. But, there are meager efforts from the kinetic
and mechanistic details on the surfactant-catalyzed oxidation of
D-sucrose by N-bromosuccinimide. Kinetic studies in surfac-
tant media can provide mechanistic details about hydrophobic
and electrostatic influences not only on redox reactions but also
on biological electron transfers that take place on membrane
surfaces or at protein-substrate interfaces. In the present work, I
report the kinetics and mechanism of the redox reaction of NBS
and D-sucrose in the absence and presence of micellar media.
Important objectives of this study were to find the effect of vari-
ous surfactants, find the main oxidation product, and deduce the
rate law and probable reaction site in the presence of catalyst.
Kinetic study is concerned with the rate of the reaction, the in-
fluence of various conditions on these rates, and mechanisms by
which a reaction occurs. The subject of chemical kinetics covers
not only reaction rate but also a wide range of studies, which
includes empirical studies of the effects of the concentrations,
temperature, pH, and catalyst on reactions of various types. It
has proved to be the best means of study of various reactions
such as oxidation, thermal decomposition, halogenation, and hy-
drogenation. For large-scale production of compounds, it is very
Received 12 September 2011; accepted 24 March 2012.
The author gratefully wishes to thank the Chhattisgarh Council of
Science and Technology (CGCOST) for the Research Project Grant.
The author also thanks Professor Laurence S. Romsted, Department
of Chemistry, Wright–Rieman Laboratories (New Jersey, USA) for
valuable discussions and fruitful suggestions.
Address correspondence to Minu Singh, Department of Chemistry,
Kalyan Post Graduate College, Sec.-7, Bhilai Nagar, Durg (Chhattis-
garh) 490006, India. E-mail: minu05111984@gmail.com
EXPERIMENTAL
Materials
D-sucrose, cetyltrimethylammonium bromide (CTAB),
sodium dodecylsulfate (SDS), tritonX-100 (TX-100), potassium
1315

1316
M. SINGH
SCH. 1. Products of D-sucrose oxidation.
chloride (KCl), potassium bromide (KBr), sodium sulfate
Na2SO4), succinimide (NHS), potassium iodide, H2SO4,
rate-determining step, is hydrolyzed to aldonic acid in neutral
medium in a fast step.
(
glacial acetic acid (all AR, s. d. fine, India), mercuric acetate 2. Paper chromatography[36]: Generally, a paper chromato-
(
Hg(OAc)2, Loba chemie, India), sodium thiosulfate AR (Quali-
graphic technique is used to identify the oxidation products
of carbohydrates. Therefore, paper chromatography was car-
ried out using n-butanol-acetic acid-water (4:1:5) as eluent
to confirm the lactone formation. Silver nitrate, sodium hy-
droxide, and sodium thiosulfate were used as detectors.
gens ExcelaR, Qualigens fine chemicals, India), and all other
chemicals used were of highest purity available commercially.
NBS (Aldrich, Germany) solution was standardized iodomet-
rically and stored in a black-coated bottle to avoid any photo-
chemical deterioration.
distilled water.
[
32]
[37]
Solutions were prepared in doubly 3. Dinapthol-sulfuric acid test : The test was carried out by
treating a little amount of the final reaction mixture with a
few drops of β,β’-dinapthol solution in concentrated sulfuric
◦
acid and then heating for an hour in a water bath at 85 C.
Procedure and Kinetic Measurements
It did develop a characteristic green fluorescence of aldonic
acid.
Solutions of the oxidant and reaction mixtures containing
the known quantities of the substrate (S) (i.e., D-sucrose), cata-
lyst (surfactant), under the kinetic conditions, [D-sucrose]T ꢁ
Thus, I may safely conclude that the primary oxidation prod-
uct is lactone in acidic medium that hydrolyzed in the alkaline
medium, leading to the formation of aldonic acid in a fast step.
[
NBS]T, acid and other necessary chemicals were separately
◦
◦
thermostated at 45 C (± 0.1 C). The reaction was initiated by
mixing the requisite amounts of the oxidant with the reaction
mixture. Progress of the reaction was monitored by following Determination of Critical Micelle Concentration
the rate of disappearance of NBS by iodometric method. The by Conductivity Measurements
pseudo-first-order constants (kobs) were calculated as usual. Un-
der the experimental conditions, possibility of decomposition
of the surfactants by NBS has been investigated and the rate
of decomposition has been found negligible. The kinetic runs
were carried out in glass stoppered bottle coated black from
outside.[ The course of reaction was studied for at least two
half-lives. The pseudo-first-order rate constants, calculated from
linear plots of log [NBS] versus time, were reproducible within
Micelles only form when the concentration of surfactant is
greater than the critical micelle concentration (CMC). The for-
mation of micelles can be understood using thermodynamics:
micelles can form spontaneously because of a balance between
entropy and enthalpy. Broadly speaking, above the CMC, the
entropic penalty of assembling the surfactant molecules is less
than the entropic penalty of caging the surfactant monomers with
water molecules. The CMC, above which micelles are present
32]
±
2.5%.
in solution, is also key to the industrial use or biological activity
of the surfactant.[
38–44]
CMC values of surfactants were deter-
◦
Stoichiometry and Product Analysis
mined conductometrically at 45 C. A digital conductivity meter,
model 611E, made the conductivity measurements of surfactant
solutions. The CMC values of surfactants were obtained from
the break point of nearly two straight-line portions of the plot
of specific conductivity versus surfactant concentration. Exper-
iments were made under different conditions and the respective
CMC values are summarized in Table 1.
Reaction mixtures with varying ratios of NBS to D-sucrose
were equilibrated at room temperature in the presence of H2SO4
for 72 h. Stoichiometry showed that 1 mol of D-sucrose
consumed 2 mol of oxidant, confirming the stoichiometry
(Scheme 1).
Under the kinetic conditions (i.e., [D-sucrose]T ꢁ [NBS]T),
qualitative identification of the reaction product was carried out
by FeCl3-HCl blue test, paper-chromatography, and dinapthol-
sulfuric acid test.
RESULTS AND DISCUSSION
Preliminary observations showed that the solution of CTAB
became turbid in presence of HClO4. Turbidity increases with
. 1. FeCl3-HCl blue test[33]: After the kinetic experiment was
1
[HClO4] at constant [CTAB]. Therefore, H2SO4 was used to
completed, a part of the oxidized reaction mixture was treated
with alkaline hydroxylamine solution. To the other part of
the reaction mixture, barium carbonate was added to make
maintain the acidic strength constant.
[
34]
the solution neutral.
FeCl3 solution that had been col- Dependence on [D-sucrose]
ored violet with phenol when added to this reaction mixture
The effect of varying the concentrations of D-sucrose on rate
[
35]
gave a bright-yellow coloration,
indicating the presence in aqueous and micellar media showed that the reaction order
of aldonic acid. It is concluded that lactone, formed in the is fractional. Further, a plot of log kobs versus log [D-sucrose]

OXIDATIVE KINETICS OF D-SUCROSE
1317
TABLE 1
Values of critical micellar concentration (CMC)
4
103,
105,
1
0 ,
CTAB
mol.L
SDS
mol.L
TX-100
mol.L
−
1
−1
−1
Solutions
(
(
(
(
(
(
i) Water
ii) sucrose
iii) NBS
iv) Acetic acid (v/v)
v) H2SO4
10.3
7.97
9.90
9.0
8.20
6.70
9.15
6.64
9.45
2.26
1.57
5.59
32.0
31.3
28.8
1.66
1.27
2.92
vi) sucrose + NBS + acetic
acid% (v/v) + H2SO4
−
−4
2
−1
Reaction conditions: [sucrose] = 2.5 × 10 mol.L , [NBS] =
−
−
4
−1
−1
−1
2
0
.0 × 10 mol.L , [Hg(OAc)
2
] = 5.0 × 10 mol.L , [H
2
SO
4
] =
−
2
−1
FIG. 2. Effect of [NBS] on sucrose oxidation; [sucrose] = 2.5 × 10 mol.L
,
4
◦
.5 × 10 mol.L , acetic acid (30% [v/v]). Literature value at 25 C
−
4
−1
−4
−1
[
H2SO4] = 0.5 × 10 mol.L , [Hg(OAc)2] = 5.0 × 10 mol.L , (ꢀ)
−
−1
.
4
−1
−3
−1
;
CMC of CTAB is 9.2 × 10 mol.L ; SDS is 8.3 × 10 mol.L
TX-100 is 0.2 × 10 mol.L
−3
−1
absence of surfactants, (ꢁ) [CTAB] = 1.2 × 10 mol.L , (ꢂ)[SDS] =
−
3
−2
−1
−3
−1
1
.0 × 10 mol.L , (•)[ TX-100] = 1.0 × 10 mol.L , 30% (v/v) acetic
◦
acid, temperature 45 C.
was linear with a slope less than unity (Figure 1). The results
are summarized in Table 2.
order dependence of the rate on [H2SO4]. The results are sum-
marized in Table 2.
Dependence on [NBS]
Dependence on Solvent
The reaction is of first order in [NBS] in the absence and
presence of surfactant as indicated by the linearity of a plot of
log [NBS] versus time (Figure 2). This was further confirmed
by the fact that the first-order rate constant is invariant with
different initial concentrations of NBS (Table 2).
The rate constant decreased with increasing acetic acid con-
tent (20–50% [v/v]). The results are summarized in Table 2. A
plot of log kobs versus 1/ε was linear with a negative slope[
45]
(Figure 4, Eq. 1). Blank experiments performed showed that the
oxidation of acetic acid by NBS during the period of study was
negligible.
Dependence on [H2SO4]
The rate constant decreased with increasing [H2SO4]. A plot
of log kobs versus log [H2SO4] was linear with a slope is negative
2
ZAZBe N
1
ꢂ
log kobs = log k −
× ε
[1]
0
2
.303 (4πε0) dAB RT
(Figure 3) and less than unity indicating a negative fractional-
−
−1
4
−1
−2
−1
−1
FIG. 1. Effect of [sucrose] with NBS; [NBS] = 2.0 × 10 mol.L , [H2SO4]
FIG. 3. Effect of [H2SO4]; [sucrose] = 2.5 × 10 mol.L , [NBS] = 2.0 ×
−
4
−1
−4
−4
−1
−4
=
0.5 × 10 mol.L , [Hg(OAc)2] = 5.0 × 10 mol.L , (ꢀ) absence of sur-
10 mol.L , [Hg(OAc)2] = 5.0 × 10 mol.L , (ꢀ) absence of surfactants,
−
−1
3
−1
−2
−1
◦
−3
−1
−2
−1
◦
factants, (ꢁ) [CTAB] = 1.2 × 10 mol.L , (ꢂ)[SDS] = 1.0 × 10 mol.L
,
(ꢁ) [CTAB] = 1.2 × 10 mol.L , (ꢂ) [SDS] = 1.0 × 10 mol.L , (•)
•) [TX-100] = 1.0 × 10− mol.L , 30% (v/v) acetic acid, temperature 45 C.
3
[TX-100] = 1.0 × 10 mol.L , 30% (v/v) acetic acid, temperature 45 C.
−3
−1
(

1318
M. SINGH
TABLE 2
◦
Effect of substrate, oxidant, solvent, and H2SO4 on kobs at 45 C
1
04, kobs s−1
2
4
4
1
0 , [sucrose]
10 , [NBS]
10 , [H2SO4]
%, acetic acid
(v/v)
−1
−1
−1
Aqueousa
CTABb
SDSc
TX-100d
mol.L
mol.L
mol.L
1
2
5
1
2
2
.0
.5
.0
0.0
0.0
.5
2.0
0.5
30
30
30
0.36
0.56
0.74
0.98
1.12
0.57
0.56
0.56
0.55
0.55
0.77
0.56
0.41
0.28
0.20
—
1.13
1.78
2.48
3.40
4.49
1.80
1.78
1.78
1.78
1.78
2.85
1.78
1.46
1.08
0.84
0.66
1.91
1.86
1.78
1.64
1.47
0.28
0.35
0.49
0.66
0.85
0.36
0.35
0.35
0.35
0.35
0.48
0.35
0.29
0.19
0.12
—
1.59
2.35
3.15
4.66
5.97
2.36
2.35
2.35
2.34
2.34
3.47
2.35
1.87
1.21
0.84
—
1.0
0.5
2.0
3.0
4.0
5.0
2.5
2.0
0.25
0
1
2
5
.50
.0
.50
.0
1
0.0
0.5
2.5
2.0
20
0.61
0.59
0.56
0.53
0.49
0.41
0.38
0.35
0.33
0.30
2.58
2.46
2.35
1.76
1.36
25
30
40
50
a
−4
−1
b
−4
−1
−3
Reaction conditions: [Hg(OAc)
2
] = 5.0 × 10 mol.L . Reaction conditions: [Hg(OAc)
2
−1
] = 5.0 × 10 mol.L , [CTAB] = 1.2 × 10
−
1
c
−4
−1
−2
d
mol.L . Reaction conditions: [Hg(OAc)
2
] = 5.0 × 10 mol.L , [SDS] = 1.0 × 10 mol.L . Reaction conditions: [Hg(OAc)
2
] = 5.0 ×
−
4
−1
−3
−1
10
mol.L , [TX-100] = 1.0 × 10 mol.L
.
ꢂ
Where k0 is the rate constant in a medium of infinite dielectric
constant, ZA and ZB are the charges of reacting ions, dAB refers
to the size of activated complex, T is absolute temperature, and
ε is the dielectric constant of the medium.
Dependence on [Hg(OAc)2]
Mercuric acetate was added to the reaction mixture as scav-
−
enger to eliminate Br formed in the reaction, which could have
produced Br2 in the reaction. The Br2 thus formed might cause
another parallel oxidation. Hg(OAc)2 thus ensures the oxidation
purely through NBS.
Dependence on [succinimide]
The reaction rate is retarded by the addition of succinimide
(NHS), which is one of the products of the reaction. This points
−
−1
2
to the existence of a pre-equilibrium step (Eq. 2):
FIG. 4. Effect of acetic acid% on sucrose oxidation; [sucrose] = 2.5 × 10
−
1
−4
−1
−4
mol.L , [NBS] = 2.0 × 10 mol.L , [H2SO4] = 0.5 × 10 mol.L
,
−
4
−1
[
=
Hg(OAc)2] = 5.0 × 10 mol.L , (ꢀ) absence of surfactants, (ꢁ) [CTAB]
K1
−
3
−1
−2
−1
6
1.2 × 10 mol.L , (ꢂ) [SDS] = 1.0 × 10 mol.L , (•) [TX-100] =
NBS + H O
5 HOBr + NHS
[2]
2
−
3
−1
◦
1
.0 × 10 mol.L , temperature 45 C.

OXIDATIVE KINETICS OF D-SUCROSE
1319
TABLE 3
Effect of temperature on kobs
1
04, kobs s−1
◦
(Aqueousa)
(CTABb)
(SDSc)
(TX-100)d
C, temperature
30
35
40
45
50
0.22
0.29
0.47
0.56
0.90
0.68
0.90
1.15
1.78
2.09
0.13
0.17
0.29
0.35
0.54
1.0
1.32
1.82
2.35
3.10
Activation parameters
−
3
1
Ea(kJ mol )
54.59
4.71
51.94
326.63
155.81
46.18
3.84
43.54
317.04
144.36
55.35
4.64
52.71
330.53
157.82
45.13
3.78
42.49
314.73
142.57
−1
−1
log pz (dm mol sec )
−
1
ꢀ
H(kJ mol )
− −1
1
–
ꢀ
ꢀS(JK mol )
−
1
G(kJ mol )
a
−2
−1
−4
−1
−2
−4
−1
Reaction conditions: [sucrose] = 2.5 × 10 mol.L , [NBS] = 2.0 × 10 mol.L , [H
2
−1
SO
4
] = 0.5 × 10 mol.L , [Hg(OAc)
2
] =
] =
−
4
−1
b
−4
−1
5
0
.0 × 10 mol.L , 30% acetic acid (v/v). Reaction conditions: [sucrose] = 2.5 × 10 mol.L , [NBS] = 2.0 × 10 mol.L , [H
2
SO
4
−
4
−1
−4
−1
−3
−1
c
.5 × 10 mol.L , [Hg(OAc)
2
] = 5.0 × 10 mol.L , [CTAB] = 1.2 × 10 mol.L , 30% acetic acid (v/v). Reaction conditions: [sucrose]
SO ] = 5.0 × 10 mol.L , [SDS] = 1.0 ×
] = 0.5 × 10 mol.L , [Hg(OAc)
mol.L , 30% acetic acid (v/v). Reaction conditions: [sucrose] = 2.5 × 10 mol.L , [NBS] = 2.0 × 10 mol.L , [H SO ] = 0.5 ×
mol.L , [Hg(OAc)
] = 5.0 × 10 mol.L , [TX-100] = 1.0 × 10 mol.L , 30% acetic acid (v/v).
−
2
−1
−4
−1
−4
−1
−4
−4
−1
−1
=
2.5 × 10 mol.L , [NBS] = 2.0 × 10 mol.L , [H
2
4
2
−
−
2
4
−1
−1
d
−2
−1
−1
10
2
4
−4
−1
−3
10
2
The positive bromine from NBS can be transferred to the D- the complex of D-sucrose-NBS has the negative charge. The
sucrose through the intermediate formation of HOBr.
cationic head group may form an ion pair with the reactive
and existing complex of D-sucrose-NBS. As a result, a large
number of D-sucrose-NBS complexes are incorporated into the
small volume of cationic micelles. But, the non-ionic micelle
form hydrogen bond with the D-sucrose-NBS complex. In the
presence of SDS, on the other hand, there is electrostatic re-
pulsion between the negative head group of SDS micelles and
the reactive species of D-sucrose-NBS complex. The result is
that slightly inhibitory effect is possible. A higher value of Ea in
the presence of SDS shows the slightly inhibitory effect on the
rate of reaction whereas a low value in the presence of CTAB
and TX-100 shows the catalytic effect. The large negative value
Dependence on [salt]
Added salts inhibit the micellar catalysis, which is a general
phenomenon. The inhibition has been explained by assuming
that the counterions compete with an ionic reactant for a site
on the micelle[ and cause shape change from spherical to
rod-like micelles. The added salts (KCl, KBr, and Na2SO4)
inhibit the rate of reaction. As the concentration of these elec-
trolytes increases, the concentration of reactants at the reac-
tion site decreases because these are responsible for rate inhibi-
tion of micellar-mediated reactions due to the exclusion of the
reagent(s) from the micellar pseudophase.
46]
#
of ꢀS in the presence of CTAB and TX-100 indicates that
more ordered activated complex is formed. The fairly high pos-
#
#
itive values of ꢀH and ꢀG indicate that the transition state is
#
Assessment for Acrylonitrile Polymerization
highly solvated. The nearly same value of ꢀG in the absence
and presence of surfactant indicated operation of similar reac-
tion mechanism in both cases. Here, Ea is energy of activation,
Addition of acrylonitrile to the reaction mixture does not
induce polymerization. Therefore, the reaction does not involve
the formation of free radicals. The observations demonstrate
that no free radicals are formed in the reaction mechanism.
#
#
ꢀ
H is enthalpy of activation, ꢀS is entropy of activation, and
#
ꢀ
G is free energy of activation.
Temperature Effect and Activation Parameters
Mechanism
◦
The oxidation of D-sucrose was studied at 30–50 C and the
The monosaccharides are considered as a unit of disac-
data are presented in Table 3. Arrhenius parameters evaluated charides and on hydrolysis disaccharides give monosaccha-
from linear plots of log kobs versus 1/T were computed from ride units. D-sucrose hydrolyzes into two monosaccharides—
Arrhenius and Eyring equations (Figure 5) in Table 3. The cat- glucose and fructose. The monosaccharides are considered as
alytic behavior of CTAB and TX-100 micelles indicates that a polyol and the reactivities of –OH groups can be influenced

1320
M. SINGH
SCH. 3. Reactive species of NBS in aqueous acidic medium.
In Scheme 4 (Eqs. 7–13), S stands for D-sucrose, K1, K2
are the equilibrium constant for the steps 1 and 2, k is the
−
rate constant, and A is intermediate species. Equation 14 is
in good agreement with the experimental results. The rate of
disappearance of [NBS] can be expressed in Eq. 15. Equations
16 and 17 satisfactorily explain the kinetic results with respect
to [NBS], [D-sucrose], [H SO ], and [NHS].
−
2
−1
FIG. 5. Effect of temperature; [sucrose] = 2.5 × 10 mol.L , [NBS] =
−
4
−1
−4
−1
2
.0 × 10 mol.L , [H2SO4] = 0.5 × 10 mol.L , [Hg(OAc)2] = 5.0 ×
4
−
−1
−3
−1
,
1
(
(
0
mol.L , (ꢀ) absence of surfactants, (ꢁ) [CTAB] = 1.2 × 10 mol.L
−
2
−1
−3
−1
ꢂ) [SDS] = 1.0 × 10 mol.L , (•) [TX-100] = 1.0 × 10 mol.L , 30%
2
4
v/v) acetic acid.
d [NBS]
dt
kK1K2 [D-sucrose] [NBS]T
−
=
by the presence of the carbonyl group. Monosaccharides exist
mainly as pyranoid and furanoid forms (Scheme 2), the for-
+
+
[NHS] [H ] + K1K2 [D-sucrose] + K1 [H ]
[14]
[
47]
mer being more stable. On the other hand, NBS also exists
in the different forms (Scheme 3, Eqs. 3–6) in aqueous acidic
medium.[
−
Where, [NBS]T = [NBS] + [HOBr] + [A ]
48]
rate = kobs[NBS]
[15]
T
When HOBr is taken as the reactive species, the rate law ex-
plains the negative effect of [H2SO4] and [NHS]. Thus, HOBr
is taken as the most reactive species, which gave the rate law
capable of explaining all the kinetic observations and other ef-
fects. According to previous experimental conditions HOBr
is the most reactive species of NBS and considering the fact
that one mole of D-sucrose is oxidized by 2 mol of NBS in
Scheme 4.
rate
kobs =
[
NBS]T
kK1K2[D-sucrose]
= [
NHS] [H ] + K1K2[D-sucrose] + K [H ]
+
+
1
[16]
+
+
1
[H ] [NHS]
kK1K2[D-sucrose]
[H ]
1
=
+
+ k
[17]
kobs
kK2[D-sucrose]
SCH. 2. Species of D-sucrose.

OXIDATIVE KINETICS OF D-SUCROSE
1321
SCH. 4. Mechanism of oxidation of D-sucrose(glucose+ fructose) by NBS.

1322
M. SINGH
−
−1
2
−1
,
FIG. 6. Effect of [CTAB] on sucrose oxidation; [sucrose] = 2.5 × FIG. 7. Effect of [SDS] on sucrose oxidation; [sucrose] = 2.5 × 10 mol.L
−
−
2
4
−1
−4
−1
−4
−1
−4
1
1
0
0
mol.L , [H2SO4] = 0.5 × 10
mol.L , [Hg(OAc)2] = 5.0 ×
[H2SO4] = 0.5 × 10 mol.L , [Hg(OAc)2] = 5.0 × 10 mol.L , [NBS] =
−1
−4
−1
−4
−1
◦
mol.L , [NBS] = 2.0 × 10 mol.L , 30% (v/v) acetic acid, tem-
2.0 × 10 mol.L , 30% (v/v) acetic acid, temperature 45 C.
◦
perature 45 C.
SDS, a representative anionic surfactant, retards the D-
sucrose oxidation path. In the SDS catalyzed path, SDS re-
stricts the negatively charged NBS-D-sucrose complex in aque-
ous phase and thus the accumulated neutral substrate in the
Dependence on [surfactants] ([CTAB], [SDS], and
[TX-100])
Cetyltrimethylammonium bromide (CTAB, a representative micellar phase (Stern layer) cannot participate in the reaction
cationic surfactant) is found to accelerate D-sucrose oxidation rate is retarded. The plot of kobs(T) versus [SDS]T (cf. Figure 7,
path. Plots of kobs(T) versus [CTAB]T (cf. Figure 6, Table 4) Table 4) shows a continuous decrease up to the concentration of
shows a continuous increase and finally it tends to level off SDS.
at higher concentration of CTAB. The rate acceleration arises
In presence of the non-ionic surfactant TX-100, both reac-
due to the preferential partitioning of the negatively charged D- tants (i.e., D-sucrose [a hydrophilic substance] and NBS) are
sucrose-NBS complex (by electrostatic attraction) and neutral preferably partitioned in the Stern layer of TX-100 (a non-ionic
substrate in the micellar surface.
surfactant), bearing not any charge on micellar head groups and
TABLE 4
Effect of surfactants on kobs
3
1
0 , [TX-100]
1
03, [CTAB] mol.L−1
10 , kobs s
4
−1
10 , [SDS] mol.L
2
−1
10 , kobs s
4
−1
mol.L
−1
10 , kobs s
4
−1
0
0
0
0
0
1
1
1
1
0.56
0.67
0.73
0.90
1.27
1.64
1.78
1.49
1.39
0
0.56
0.46
0.44
0.40
0.38
0.36
0.35
0.34
0.33
0
0.56
0.60
0.70
1.13
1.79
2.35
2.66
2.90
2.96
2.97
.2
.4
.6
.8
.0
.2
.4
.6
0.2
0.4
0.6
0.75
0.8
1.0
1.1
1.2
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1
.8
Other parameters
−
1
−4
kw, s (10 )
0.54
3.95
0.69
6.74
0.40
3.58
3
−1
(
KS+KO), dm mol
−6
(
10 )
−
2
−1
−4
−1
−3
−4
−1
Reaction conditions: [sucrose] = 2.5 × 10 mol.L , [NBS] = 2.0 × 10 mol.L , [H
2
SO
4
] = 0.5 × 10 mol.L , [Hg(OAc)
2
] = 5.0 ×
−
4
−1
◦
−4
◦
10
mol.L , 30% acetic acid (v/v), temperature 45 C. Ac)
2
] = 5.0 × 10 mol dm , 30% acetic acid (v/v), temperature 45 C.

OXIDATIVE KINETICS OF D-SUCROSE
1323
SCH. 5. Schematic model showing probable location of reactants.
consequently the rate is accelerated (Figure 8, Table 4). A possi- The Kinetic Model to Explain the Micellar Effects
ble arrangement (although highly schematic) could be as shown
Micellar catalysis critically depends on the interactions of
in Scheme 5, which indicates the probable reaction site to be the the micelle with the substrate(s) and the activated complex.
Stern and Gouy-Chapman layers junctural region.
This is an extremely complicated problem because a number
of different interactions are involved including those associ-
ated with the headgroup of the surfactant, different segments
of the alkyl chain and the counterions. In Berezin’s model,[
a solution above the CMC may be considered as a two-phase
system, consisting of an aqueous phase and a micellar pseu-
dophase. The reactants (S and O) may be distributed as shown in
Scheme 6.
49]
A quantitative rate expression for a bimolecular reaction oc-
curring only in aqueous (kW path) and micellar (kM path) phase
−
−1
2
−1
,
FIG. 8. Effect of [TX-100] on sucrose; [sucrose] = 2.5 × 10 mol.L
−
4
−1
−4
[
H2SO4] = 0.5 × 10 mol.L , [Hg(OAc)2] = 5.0 × 10 mol.L , [NBS] =
−
4
−1
◦
2
.0 × 10 mol.L , 30% (v/v) acetic acid, temperature 45 C.
SCH. 6. Berezin’s model.

1324
M. SINGH
−
1
FIG. 9. Plot between (csurf-CMC) versus kobs (For CTAB); [sucrose] =
−
1
−
2
−1
−4
−1
FIG. 11. Plot between (csurf-CMC) versus kobs
(tor TX-100); [sucrose]
2
.5 × 10 mol.L , [NBS] = 2.0 × 10 mol.L , [H2SO4] = 0.5 ×
4
−
2
−1
−4
−1
−
−1
−4
−1
= 2.5 × 10 mol.L , [NBS] = 2.0 × 10 mol.L , [H2SO4] = 0.5 ×
1
0
mol.L , [Hg(OAc)2] = 5.0 × 10 mol.L , 30% (v/v) acetic acid,
−
4
−1
−4
−1
◦
10 mol.L , [Hg(OAc)2] = 5.0 × 10 mol.L , 30% (v/v) acetic acid,
temperature 45 C.
◦
temperature 45 C.
for the pseudo-first-order rate constant is given as
ꢂ
that kW ꢁ kMKSKO(Csurf – CMC) so that the Eq. 18 takes the
ꢂ
following form:
kw + k KSKO (CSurf − CMC)
M
kobs
[18]
[
1 + Ks (Csurf − CMC)] [1+KO (CSurf − CMC)]
kobs
Where KS and KO are the association constants of D-sucrose
and NBS, respectively, with surfactants; CSurf is the analytical
kw
=
2
[
1 + (KS + KO) (Csurf − CMC)] + KSKO (CSurf − CMC)
ꢂ
concentration of surfactants, kM = (kM/V), V being molar vol-
[
19]
ume of the micelle; and kW and kM are the pseudo-first-order
rate constants in the absence and presence of micelles, respec-
tively. Because the oxidant will be uncharged species and the
substrate is large molecules, the hydrophobic and electrostatic
interactions will be large and hence it may be expected that KS
and K0 will be high. Because CSurf is small it may be possible
Again, because (Csurf – CMC) is very small, the terms containing
Csurf – CMC) may be neglected, and Eq. 19 may be rearranged
2
(
to
1
1
K + K
S
O
=
+
(CSurf − CMC)
[20]
kobs
kw
Kw
−
1
The plot of k versus (Csurf – CMC) for D-sucrose is linear
obs
(Figures 9, 10, and 11, Table 4).
CONCLUSION
With the D-sucrose oxidation reaction by NBS, a neutral
species HOBr was found to act as the active oxidant to give the
product lactone of aldonic acid. This neutral species reacts with
the substrate D-sucrose to form a complex that subsequently
experiences electron-transfer redox decomposition in the rate
determining step. The effect of the cationic, anionic, and non-
ionic surfactants was followed and the observed micellar effects
are in agreement with the proposed reaction. Activation and
thermodynamic parameters were evaluated for both in the ab-
sence and presence of the surfactants. The CMC values are
lower than those given in the literature for aqueous solutions of
surfactants without added electrolyte. The mechanism of the re-
action involves (a) hydrolysis of D-sucrose into monosaccharide
−
−1
1
FIG. 10. Plot between (csurf − CMC) versus kobs (tor SDS); [sucrose] =
−
2
−1
−4
−4
2
.5 × 10 mol.L , [NBS] = 2.0 × 10 mol.L , [H2SO4] = 0.5 × 10
−
1
−4
−1
mol.L , [Hg(OAc)2] = 5.0 × 10 mol.L , 30% (v/v) acetic acid, temperature
◦
4
5 C.

OXIDATIVE KINETICS OF D-SUCROSE
1325
units—glucose and fructose and (b) oxidation of both monosac- 15. Pottenger, C.R.; Johnson, D.C. Mechanism of cerium (IV) oxidation of
glucose and cellulose. J. Polym. Sci. Part A 1968, 8, 301–318.
charide units. The effect of micellization can be correlated with
1
6. Singh, S.V.; Saxena, O.C.; Singh, M.P. Mechanism of copper(II) oxidation
of reducing sugars. I. Kinetics and mechanism of oxidation of D-xylose, L-
arabinose, D-glucose, D-fructose, D-mannose, D-galactose, L-sorbose, lac-
tose, maltose, cellobiose, and melibiose by copper(II) in alkaline medium.
J. Am. Chem. Soc. 1970, 92, 537–541.
the nature of the reducing substrates and the reaction conditions.
This is in agreement with the qualitative knowledge about the
nature of D-sucrose and NBS in micellar medium.
1
7. Isbell, H.S.; Frush, H.L. Reaction of carbohydrates with hydroperoxides:
part II. Oxidation of ketoses with the hydroperoxide anion. Carbohydr. Res.
SAFETY
N-Bromosuccinimide is sensitive to light. With that, the NBS
1
973, 28, 295–301.
and reaction mixture both were stored in a black-coated bottle 18. Mehrotra, R.N.; Amis, E.S. Kinetics of oxidation of aldo sugars by Ce(IV)
in aqueous sulfuric acid. J. Org. Chem. 1974, 39, 1788–1791.
to avoid any photochemical deterioration.
1
9. Sen Gupta, K.K.; Sen Gupta, S.; Basu, S.N. Kinetics and mechanism of
oxidation of some aldoses by chromic acid in perchloric acid medium.
Carbohydr. Res. 1979, 71, 75–84.
REFERENCES
1
2
3
. Ahmed, M.; Subramani, K. Kinetics of oxidation of cobalt(III) complexes
of α-hydroxy acids by hydrogen peroxide in the presence of surfactants.
E.-J. Chem. 2008, 5, 43–51.
. Mohana, K.N.; Bhandarkar, P.M.R. Oxidation of 2-phenylethylamine with
N-bromosuccinimide in acid and alkaline media: a kinetic and mechanistic
study. J. Chin. Chem. Soc. 2007, 54, 1223–1232.
20. (a) Sen Gupta, K.K.; Basu, S.N. Kinetics and mechanism of oxidation
of some aldoses by vanadium(v) in perchloric acid medium. Carbohydr.
Res. 1979, 72, 139–149. (b) 20 Sen Gupta, K.K.; Basu, S.N. Kinetics
and mechanism of oxidation of D-glucose and D-ribose by chromium(VI)
and vanadium(V) in perchloric acid medium. Carbohydr. Res. 1980, 80,
223–232. (c) 20 Sen Gupta, K.K.; Basu, S.N. Kinetics and mechanism of
oxidation of D-erythrose and DL-glyceraldehyde by chromium(VI) and
vanadium(V) in perchloric acid medium. Carbohydr. Res. 1980, 86, 7–16.
. Keyvanfard, M. Kinetic-spectrophotometric determination of trace amounts
of vanadium (V) based on its catalytic effect on the oxidation of victoria
blue B by potassium bromate in micellar medium. World Appl. Sci. J. 2009, 21. Sen Gupta, K.K.; Basu, S.N.; Sen Gupta, S. Kinetics and mechanism of
6
, 624–629.
. Shukla, P.; Upadhyay, S.K. Kinetics of oxidation of non-ionic surfactants
tritonx-100 and brij-35) by KMnO4 in H2SO4 medium. Ind. J. Chem.
008, 47A, 1037–1040.
oxidation of D-fructose and D-sorbose by chromium(VI) and vanadium(V)
in perchloric acid medium. Carbohydr. Res. 1981, 97, 1–9.
22. Virtanen, P.O.I.; Kurkisuo, S. Oxidation of D-fructose with vanadium(V):
a kinetic approach. Carbohydr. Res. 1985, 138, 215–223.
23. Gennis, R.B. Biomembranes: Molecular Structure and Function; New
York: Springer-Verlag, 1989.
4
5
6
7
8
(
2
. Malik, M. A.; Khan, Z. Submicellar catalytic effect of cetyltrimethylam-
monium bromide in the oxidation of ethylenediaminetetraacetic acid by
MnO4. Colloids Surf. B: Biointerf. 2008, 64, 42–48.
24. Darnell, J.; Lodish, H.; Baltimore, D. Molecular Cell Biology; New York:
. Mushran, S. P.; Bose, A. K.; Tiwari, J. S.T. Kinetics and mechanism oi
Scientific American Books, 1990.
oxidation o∼cyclopentanone by N-bromosuccinimide. Monat. fiir Chemic 25. Alberts, B.; Bray, D.; Lewis, J.; Raff, M.; Roberts, K.; Watson, J.D. Molec-
976, 107, 1021–1027.
ular Biology of the Cell; New York: Garland, 1994.
. Bhandarkar, P.M.R.; Mohana, K.N. Oxidative cleavage of gabapentin with 26. Trombottoa, S.; Violet-Courtens, E., Cottier, L.; Queneau, Y. Oxidation of
1
N-bromosuccinimide in acid medium: a kinetic and mechanistic study. Ind.
J. Chem. 2009, 48A, 1107–1112.
. Ramachandrappa, R.; Puttswamy; Mayanna, S.M.; Gowda, N.M.M. Ki-
netics and mechanism of oxidation of aspirin by bromamine-T, N-
bromosuccinimide and N-bromosuccinimide. Int. J. Chem. Kinet. 1997,
two major disaccharides: sucrose and isomaltulose. Topics Catal. 2004, 27,
31–37.
27. Odebunmi, E.O.; Iwarere, S.A.; Owalude, S.O. Kinetics of oxida-
tion of fructose, sucrose and maltose by potassium permanganate in
NaHCO /NaOH buffer and iridium (IV) complex in sodium acetate/ acetic
3
3
0, 407–414.
acid buffer. Int. J. Chem. 2006, 16, 167–176.
9
. Park, M.-S.; Choi, C.-U. Hofmann rearrangement by using N-
bromosuccinimide-silveracetate in DMF. Arch. Pharm. Res. 1993, 16,
28. Parpot, P.; Kokoh, K.B.; Belgsir, E.M.; Leger, J.-M.; Beden, B.; Lamy, C.
Electrocatalytic oxidation of sucrose: analysis of the reaction products. J.
Appl. Electrochem. 1997, 27, 25–33.
1
52–154.
1
1
1
1
0. Sengupta, P.K.; Pramanik, A.R. Grafting of vinyl polymers onto carbon
black using N-bromosuccinimide as thermal initiator and characterization
of the grafted product. Eur. Poly. J. 1994, 30, 421–425.
1. El-Brashy, Belal, A.; F.; Walash, M.I.; Rizk, M. Titrimetric determination
of acetylenic hypnotics using organic brominating agents. Pharm. World
Sci. 1988, 10, 90–92.
2. Sala, L.F.; Cirelli, A.; Lederkremer, R. Oxidative decarboxylation of al-
donolactones by cerium(IV) sulphate in aqueous sulphuric acid; synthesis
of D-arabinose. J. Chem. Soc., Perkin Trans. 1977, 2, 685–688.
3. Gupta, M.; Saha, S.; Banerjee, P. Kinetics and mechanism of the reduction
of dodecatungstocobaltate (III) by D-fructose, D-glucose, and D-mannose:
comparison between keto- and aldohexoses J. Chem. Soc., Perkin Trans.
29. Okoro, H.K.; Odebunmi, E.O. Kinetics and mechanism of oxidation of
sugar and sugar alcohols by KMnO . Int. J. Phys. Sci. 2009, 4, 471–
4
476.
30. Okoro, H.K.; Odebunmi, E.O. Kinetics and mechanism of oxidation of
sugar and sugar alcohols by vanadium pentoxide. Sci. Res. Ess. 2010, 5,
2588–2594.
31. E.O.; Odebunmi, S.O. Owalude Kinetics and mechanism of oxidation of
sugars by chromium(VI) in perchloric acid medium. Chern. Soc. Nigeria
2005, 30, 187–191.
32. Barakat, M.Z.; Abdel-Wahab, M.F. Microdetermination of bromine or chlo-
rine in N-halogenated imides. Anal. Chem. 1954, 26, 1973–1974.
33. (a) Sengupta, K.K.; Begum, B.A.; Pal, B.B. Kinetic behaviour and relative
reactivities of some aldoses, amino sugars, and methylated sugars towards
platinum(IV) in alkaline medium. Carbohydr. Res. 1998, 309, 303–310.
(b) 33 Abdel-Akher, M.; Smith, F. The detection of carbohydrate esters
and lactones after separation by paper chromatography. J. Am. Chem. Soc.
1951, 73, 5859–5860.
1
988, 2, 1781–1785.
1
4. (a) Sala, L.F.; Signorella, S.R.; Rizzotto, M.; Frascaroli, M.I.; Gan-
dolfo, F. Oxidation of L-rhamnose and D-mannose by Cr(VI) in per-
chloric acid. A comparative study. Can. J. Chem. 1992, 70, 2046–
2052. (b) 14 Signorella, S.R.; Rizzotto, M.; Daier, V.; Frascaroli, M.I.;
Palopoli, C.; Martino, D.; Bousseksou, A.; Sala, L.F. Comparative study
of oxidation by chromium(V) and chromium(VI). J. Chem. Soc., Dalton
Trans. 1996, 1607–1611.
34. Kumar, A.; Mehrotra, R.N. Kinetics of oxidation of aldo sugars by quin-
quevalent vanadium ion in acid medium. J. Org. Chem. 1975, 40, 1248–
1252.

1326
M. SINGH
35. Sengupta, K.K.; Begum, B.A.; Pal, B.B. Kinetics and mechanism of
the oxidation of some aldoses, amino sugars and methylated sugars by
46. Ray, A.; Nemethy, G. Effects of ionic protein denaturants on micelle for-
mation by nonionic detergents. J. Am. Chem. Soc. 1971, 93, 6787–6793.
tris(pyridine-2-carboxylato)manganese(III) in weakly acidic medium. Car- 47. Perlin, A.S. Ring contraction during the lead tetraacetate oxidation of re-
bohydr. Res. 1999, 315, 70–75.
ducing sugars. Can. J. Chem. 1964, 42, 2365–2374.
48. Jabber, S.F.A.; Rao, V.S. Kinetics of Oxidative deamination of aliphatic
amines by N-bromosuccinimide in aqueous acetic acid medium. Ind. J.
Chem. 1994, 33A, 69–71.
3
6. Sala, L.F.; Signorella, S.R.; Rizotto, M.; Frascaroli, M.I.; Gondolfo, F.
Oxidation of L-rhamnose and D-mannose by Cr(VI) in perchloric acid. A
comparative study. Can. J. Chem. 1992, 70, 2046–2052.
3
3
3
4
7. Feigl, F. Spot Tests in Organic Analysis, 5th edn.; Amsterdam: Elsevier, 49. Berezin, I.V.; Martinek, K.; Yatsimirskii, A.K. Physicochemical founda-
1
956.
8. Cordes, E.H. Kinetics of organic reactions in micelles. Pure Appl. Chem.
978, 50, 617–625.
tions of micellar catalysis. Russ. Chem. Rev. (Eng. Transl.) 1973, 42,
787–802.
1
9. Pramauro, E.; Prevot, A.B. Solubilization in micellar systems. Analytical
and environmental applications. Pure and Appl. Chem. 1995, 67, 551–559.
0. Sokolowski, A.; Kazimiera, A.W.; Urszula, K.; Rutkowski, B.; Syper, L.
Aggregation properties of cationic gemini surfactants in aqueous solution.
Physicochem. Problems Mineral Proc. 2002, 36, 51–64.
GRAPHICAL ABSTRACT:
4
1. Huibers, P.D.T.; Lobanov, V.S.; Katritzky, A.R.; Shah, D.O.; Karelson, M.
Prediction of critical micelle concentration using a quantitative structure-
property relationship approach J. Colloid Interface Sci. 1997, 187, 113–120.
2. Mukherjee, P.; Mysels, K.J. Critical Micelle Concentration of Aqueous
Surfactant Systems, NSRDS-NBS36; Washington, DC: Superintendent of
Documents, 1971.
4
4
4
3. Fendler, J.H. Membrane Mimetic Chemistry; New York: Wiley, 1982.
4. Buurma, N.J.; Serena, P.; Blandamer, M.J.; Engberts, J.B.F.N. The nature
of the micellar stern region as studied by reaction kinetics. J. Org. Chem.
2
004, 69, 3899–3906.
45. Amis, E.S. Solvent effects on reaction rates and mechanism: New York:
Academic Press, 1966.