1
134
Russ.Chem.Bull., Int.Ed., Vol. 52, No. 5, May, 2003
Bagiyan et al.
+
Table 1. Stoichiometry of reduction of O on catalytic oxidation of aminothiols (AT) in the presence of Cu ions
2
[AT]•103 [Cu ]•106
+
рН
τ/s
–∆[O ]•105
∆[AD]•105
∆[H O ]•10
5
–∆[H O ]*•10 ∆[AT]/∆[O ]**
5
AT
2
2
2
2
2
2
mol L–1
mol L–1
ESH
ESH
ESH
ESH
PSH
PSH
3
3
5
5
5
5
25.0
2.5
50.0
5.0
80.0
5.0
8.0
8.0
11.0
11.0
8.5
15
30
10
40
15
10
3.5
1.8
12.0
1.2
6.0
15.0
4.0
2.3
22.0
2.5
6.5
15.0
3.1
1.3
3.5
0.2
5.4
0.45
0.36
1.2
0.2
0.52
—
2.0
2.1
3.5
3.8
2.0
2.0
12.0
15.0
*
*
A decrease in the concentration of H O in the course of the noncatalytic reaction with aminothiol.
2 2
* ∆[AT]/∆[O ] = 2∆[AD]/∆[O ] = 2(∆[AD] – ∆[H O ])/∆[O ].
2
2
2
2
2
fides and reduction of O to H O and/or H O, and can
References
2
2
2
2
be formally described by the following equations
1
2
. G. A. Bagiyan, I. K. Koroleva, N. V. Soroka, and A. V.
Ufimtsev, Izv. Akad. Nauk, Ser. Khim., 2003, 1075 [Russ.
Chem. Bull., Int. Ed., 2003, 52, 1135].
. G. A. Bagiyan, I. K. Koroleva, and N. V. Soroka, Zh. Neorg.
Khim., 1978, 23, 416 [J. Inorg. Chem. USSR, 1978, 23 (Engl.
Transl.)].
2
4
RSH + O2
RSH + O2
RSSR + H O ,
(8)
(9)
2
2
2 RSSR + 2 H O.
2
Equation (8) corresponds to oxidation of nonchelating
aminothiols. Equations (8) and (9) correspond to oxidaꢀ
tion of chelating aminothiols, the statistical weight of
Eq. (9) being increased when catalytic oxidation is carried
3
4
. J. P. Barton and J. E. Packer, Int. J. Rad. Phys. Chem.,
1
970, 2, 259.
. S. A. Grachev and N. V. Soroka, Izv. Akad. Nauk SSSR, Ser.
Khim., 1981, 1756 [Bull. Acad. Sci. USSR, Div. Chem. Sci.,
1981, 30 (Engl. Transl.)].
I
out in an alkaline medium and the [AT]/[Cu ] ratio in
the solution is increased. It should be noted that the
+
–
[
(Cu )(RS ) ] complexes prevail in the equilibria in the
5. G. A. Bagiyan, I. K. Koroleva, N. V. Soroka, and A. V.
Ufimtsev, in Breslerovskie chteniya [Bresler Meeting], Izdꢀvo
Peterburgskogo Instituta Yadernoi Fiziki RAN, St.ꢀPetersꢀ
burg, 2002, p. 270 (in Russian).
6
7
2
reactions of all aminothiols at pH 10—12. The data on
catalytic oxidation obtained in the present study showed
that O2 coordinated in the complexes with chelating
. A. Hanaki and H. Kamide, Chem. Pharm. Bull., 1973, 21, 1421.
. J. P. Barton, J. E. Packer, and R. J. Sims, J. Chem. Soc.,
Perkin Trans. 2, 1973, 1547.
. G. A. Bagiyan, S. A. Grachev, I. K. Koroleva, and N. V.
Soroka, Izv. Akad. Nauk SSSR, Ser. Khim., 1976, 990 [Bull.
Acad. Sci. USSR, Div. Chem. Sci., 1976, 25 (Engl. Transl.)].
+
aminothiols is retained in the coordination sphere of Cu
+
until it is reduced to H O. The Cu complexes with
2
nonchelating aminothiols have, apparently, structures
8
such that O , which is initially coordinated in these comꢀ
2
+
plexes, is eliminated from the coordination sphere of Cu
once being reduced to H O .
9. G. A. Bagiyan, S. A. Grachev, I. K. Koroleva, and N. V.
Soroka, Zh. Org. Khim., 1975, 11, 900 [J. Org. Chem. USSR,
2
2
It should be emphasized that the characteristic feaꢀ
tures of the stoichiometry of catalytic oxidation were esꢀ
tablished for bidentate aminothiols whose alkaline soꢀ
1
975, 11 (Engl. Transl.)].
1
1
0. G. A. Bagiyan, S. A. Grachev, I. K. Koroleva, and N. V.
Soroka, Zh. Obshch. Khim., 1976, 46, 365 [J. Gen. Chem.
USSR, 1976, 46 (Engl. Transl.)].
1. G. A. Bagiyan, S. A. Grachev, and N. V. Soroka, Izv. Akad.
Nauk SSSR, Ser. Khim., 1975, 435 [Bull. Acad. Sci. USSR,
Div. Chem. Sci., 1975, 24 (Engl. Transl.)].
12. A. Hanaki and H. Kamide, Chem. Pharm. Bull., 1971, 19, 1006.
13. A. Hanaki, Bull. Chem. Soc. Jpn., 1995, 68, 831.
14. A. Lakshminarayanakh, Membrannye elektrody [Membrane
Electrodes], Khimiya, Leningrad, 1979, 358 pp. (in Russian).
5. G. A. Agaev and V. S. Chernomyrdin, Tekhnicheskii progress
v oblasti ochistki prirodnogo gaza ot serovodoroda okislitel´nymi
metodami [Technological Progress in Purification of Natural
Gas from Hydrogen Sulfide by Oxidative Methods], Mingazꢀ
prom, Moscow, 1980, 43 pp. (in Russian).
16. F. Haber and J. Weiss, Proc. Royal Soc., 1934, 147, 332.
17. O. V. Dyatchina, L. V. Semenyak, and Yu. I. Skurlatov, Khim.
Phys. 1992, 11, 1255 [Chem. Phys., 1992, 11 (Engl. Transl.)].
+
–
lutions with copper ions contain the [(Cu )(RS ) ]
2
complexes as the major component with the ratio
+
+
[
AT]/[Cu ] ≥ 100. In the presence of Cu complexes
with triꢀ or polydentate ligands (for example, with
–
–
H N(CH ) NH(CH ) S , H N(CH ) NH(CH ) S , or
2
2 3
2 2
2
2 2
2 2
glutathione), solutions contain predominantly the polyꢀ
+
–
+
–
nuclear [(Cu )(RS )] and [(Cu ) (RS ) ] complexes
n
2
3 m
(
see Eqs. (1) and (2)), which are inactive in catalytic
1
oxidation of aminothiols by molecular oxygen but are
very active in catalytic decomposition of H O . Actuꢀ
ally, the addition of equivalent amounts of H O to aerꢀ
1
7
2
2
2
2
ated solutions of the first two aminothiols followed by the
addition of copper ions led to vigorous decomposition of
H O and the corresponding oxidation of aminothiols.
2
2
The experimental data on the kinetics of catalytic oxiꢀ
dation of aminothiol by molecular oxygen in support of
the innerꢀsphere mechanism will be published elsewhere.
Received August 8, 2002;
in revised form January 15, 2003