2
024
DORONIN, CHERNOVA
Reaction rate constants for systems I–III in water and
sodium dodecylsulfate micelles
The chemicals used were: NaNO of “chemically
2
pure” grade, 4-nitroaniline, 4-aminobenzoic and sul-
fanilic acids were twice recrystallied from hot water;
diphenylamine of “analytically pure” grade was
recrystallized from petroleum ether; sodium dode-
cylsulfate “pure” of grade corresponding to Technical
Requirments TU 6-09-07-1816-93 and other surfa-
ctants were not additionally purified. Acetate–chloride
buffer solutions were of рН in the range 0.65–4.0.
2
–2
–1
s
k , l mol min
System
Н
2
О
Dodecylsulfate micelles
I
80±5
35±1
38±4
271±19
85±2
II
III
7.20±0.17
Here ε is the molar extinction coefficient of analytical
REFERENCES
form, ε = A/(Cl); l is the optical route length, рK = 0.9
а
for diphenylamine.
1
2
. Stepanov, B.I., Vvedenie v khimiyu and tekhnologiyu
organicheskikh krasitelei (Introduction to the Chemistry
of Organic Dyes), Moscow: Khimiya, 1971.
The calculated values of rate constants in aqueous
medium and in sodium dodecylsulfate micelles (at
optimal concentration 2×10 M, see the table) show
that azo coupling reaction in the systems I and II is
accelerated by dodecylsulfate micelles respectively
–
2
. Zhelezko, O.I. and Chernova, R.K., Aromaticheskie
aminy kak organicheskie reagenty dlya foto-
metricheskogo opredeleniya nitrite-iona v vodnykh and
mitsellyarnykh sredakh (Aromatic Amines as Organic
Reagents for Photochemical Determination of Nitrite-
Ion in Aqueous and Micellar Media), Saratov:
Nauchnaya Kniga, 2003.
~
3.4- and 2.4-fold while in the system III it is ~5-fold
decelerated, that is consistent with Hartley’s rule.
According to Hartley’s “sign rule,” the reactants
possessing charges of same sign are concentrated by
the oppositely charged micelle of surfactant, and this
leads to increase in the reaction rate (systems I and II).
When reactants are oppositely charged (system III) the
micelles of ionic surfactants will separate them leading
to the decrease in the reaction rate, as is observed for
the studied systems.
3. Shirinova, A.G. and Ivanov, V.M., Zh. Analyt. Khim.,
1994, vol. 1, no. 49, p. 266.
4. Savvin, S.B., Chernova, R.K., and Shtykov, S.N.,
Poverkhnostno-aktivnye veshchestva (Surfactants),
Moscow: Nauka, 1991.
5
6
7
8
9
. Szele I. and Zollinger H., Topics in Current Chemistry,
1983, vol. 112, p. 1.
. Tontorio, A., Gatti, B., and Carlini, F.M., Dyes and
Pigm., 1985, vol. 6, no. 2, p. 107.
EXPERIMENTAL
. Hashida, Y., Matsumura, K., Ohmori, Y., and Matsui, K.,
Electron absorption spectra and kinetic curves were
registered on a SF-46 spectrophotometer in fused glass
and glass cells with the length of the absorbing layer
Nippon Kagaku Kaishi, 1979, p. 1745.
. Sallo, A. and Tomescu, A., Revue Roumaine de Chimie,
1
985, vol. 30, nos. 9–10, p. 875.
1
–5 cm. The рН values were measured on a pH-121
. Korneeva, O.I., Chernova, R.K., and Doronin, S.Yu.,
Zh. Fiz. Khim., 2008, vol. 82, no. 4, p. 645.
device. The thermogravimetric studies of samples with
a mass 100 mg were carried out on an OD-103 deri-
vatograph in the temperature range from 20 to 1000°С
with the rate of heating 10 deg min . The IR spectra
were registered on a Fourier IR spectrometer FSM
10. Luchkevich, E.R., Mileiko, V.E., Bagal, I.L., and El’-
–
1
tsov, A.V., Zh. Obshch. Khim., 1986, vol. 56, no. 7. p. 1574.
11. Godnev, I.N., Krasnov, K.S., and Vorob’ev, N.K.,
Fizicheskaya khimiya (Physical Chemistry), Moscow:
Vysshaya Shkola, 1982.
1
201 from mulls in mineral oil and in hexa-
chlorobutadiene at 25±1°С.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 78 No. 11 2008