Kinetics and mechanism of oxidation of manganese(III) acidoporphyrin complexes with hydrogen peroxide

Article abstract of DOI:10.1134/S0036023606110192

The reactions of manganese(III) acidotetraphenylporphyrin complexes with hydrogen peroxide in an aqueous-organic medium at 288-308 K are studied by spectrophotometry. The reaction is the oxidation of the manganese(III) complex. The spectral and kinetic da

Full text of DOI:10.1134/S0036023606110192

ISSN 0036-0236, Russian Journal of Inorganic Chemistry, 2006, Vol. 51, No. 11, pp. 1820–1825. © Pleiades Publishing, Inc., 2006.
Original Russian Text ©T.N. Lomova, E.N. Kiseleva, M.E. Klyueva, 2006, published in Zhurnal Neorganicheskoi Khimii, 2006, Vol. 51, No. 11, pp. 1931–1937.
PHYSICAL METHODS
OF INVESTIGATION
Kinetics and Mechanism of Oxidation of Manganese(III)
Acidoporphyrin Complexes with Hydrogen Peroxide
T. N. Lomova, E. N. Kiseleva, and M. E. Klyueva
Institute of Solution Chemistry, Russian Academy of Sciences, ul. Akademicheskaya 1, Ivanovo, 153045 Russia
Received November 10, 2005
Abstract—The reactions of manganese(III) acidotetraphenylporphyrin complexes with hydrogen peroxide in
an aqueous–organic medium at 288–308 K are studied by spectrophotometry. The reaction is the oxidation of
the manganese(III) complex. The spectral and kinetic data correspond to a multistep mechanism including the
step of coordination of a hydrogen peroxide molecule by the central manganese atom. A possibility of forma-
tion of oxidized complexes without macrocycle destruction upon the reaction with H2O2 makes manganese(III)
porphyrins quite promising for use as models of natural catalases.
DOI: 10.1134/S0036023606110192
The studies of the catalytic activity of metal porphy- tration. The absorbance of solutions during the reaction
rins and metal phthalocyanines in hydrogen peroxide was measured at a wavelength of 468 nm at 288, 293,
decomposition [1, 2] reveal a noticeable degradation of 298, and 308 K. The temperature of the solution in the
the catalyst (achieving 30–50%) or suppression of its cell fluctuated by at most 0.1 K.
activity caused by an excess of bases, such as imida-
The apparent (kapp) and true (kv) rate constants and the
zole, added to the system. It is also indicated that redox
reaction order (n) were optimized using the ln(c0/cτ)–τ
transformations of catalysts occur during H2O2 decom-
and
–logcH O plots, respectively. The sample
2
logkapp
position. Therefore, it is pertinent to study the nature
and rates of conversion of porphyrin catalysts caused
by hydrogen peroxide. It was shown [3, 4] that metal
phthalocyanines undergo oxidative destruction by H2O2
in an acidic medium. Pheophytin and its metal com-
plexes are also oxidized but much more slowly.
of the function and 2argument pairs ranged from 12 to
25. The activation energies (E) of the reaction were
determined from the slope ratio of the straight lines in
the coordinates logk –1/T. The activation entropies
were calculated by the formula [6]
In the present work, we carried out the spectropho-
tometric and kinetic studies of the acetate and chloride
exocomplexes of manganese(III) tetraphenylporphine
with hydrogen peroxide in aqueous–organic medium at
288–308 K and substantiated the multistep process of
metal porphyrin oxidation.
E
∆E
∆S≠ = 19.1 × logkT + ----------------- – 19.1 × logT – 205.(1)
T
The equilibrium constant of the reaction of
(Cl)MnTPP with hydrogen peroxide was determined
from Eq. (2) for the three-component equilibrium sys-
tem, which was transformed into Eq. (3) using the Bou-
guer–Lambert–Beer law for a mixture of two colored
compounds:
EXPERIMENTAL
Manganese(III) complexes with tetraphenylpor-
phine (Cl)MnTPP and (AcO)MnTPP were synthesized
and purified as described earlier [5]. Electronic absorp-
tion spectra in CHCl3, λmax, nm (logε) for (Cl)MnTPP:
402 (4.64), 478 (4.98), 524 (3.81), 582 (4.00), 616
(3.03); for (AcO)MnTPP: 403 (3.61), 427 (3.48), 480
(4.98), 527 (3.70), 584 (3.94), 618 (3.97). The kinetics
of the reaction of manganese porphyrins with H2O2 was
studied by spectrophotometry. Electronic absorption
spectra of porphyrins were recorded on Hitachi
U-2000, Specord M-40, and SF-26 instruments. To pre-
pare working solutions 3 mL in volume, an aqueous
solution (1 mL) of hydrogen peroxide (19.9 mol/L) in
DMF was added to a solution (2 mL) of the complex
(Cl)MnTPP + H2O2
(Cl)(H2O2)MnTPP, (2)
(Aeq – A0)/(A∞ – A0)
1 – (Aeq – A0)/(A∞ – A0)
-----------------------------------------------------------
K =
(3)
1
------------------------------------------------------------------------------------------------
×
.
(cH O – c0(Cl)MnTPP(Aeq – A0)/(A∞ – A0))
2
2
Here, A0, A∞, Aeq are the absorbances of solutions of the
initial (Cl)MnTPP compound, (Cl)(H2O2)MnIIITPP
complex, and equilibrium mixture at the working wave-
length (468 nm).
Calculations were performed using the Origin 61
(2 × 10−5 mol/L) in DMF of the corresponding concen- and Microsoft Excel programs.
1820

KINETICS AND MECHANISM OF OXIDATION OF MANGANESE(III)
1821
467
A
A
467
1
1
520
550
679
679
566
5
5
λ, nm
λ, nm
III
Fig. 1. Electronic absorption spectra of (Cl)Mn TPP during
III
Fig. 2. Electronic absorption spectra of (Cl)Mn TPP during
the reaction with H O at 298 K and c = 1.0 mol/L. For
the reaction with H O at 298 K and c
= 0.017 mol/L:
2
2
H2O2
2
2
H2O2
(1) at the initial moment and (2) at the end of the reaction.
The other curves correspond to intermediate time moments.
designations, see Fig. 1.
Dimethylformamide (chemically pure grade) was with respect to the starting metal porphyrin was found
distilled using a vacuum pump. The initial concentra- by kinetic measurements (Fig. 4). The rate constants of
tion of H2O2 in water (19.9 0.2 mol/L) was deter- a formally first-order reaction (kapp) and their root-
mean-square deviations are presented in Table 1. In the first
mined by iodometric titration.
concentration region at cH O from 0.017 to 0.1 mol/L, a
satisfactory linear correla2tion between kapp and cH O is
observed: this correlation is, however, violated in the
2
2
2
RESULTS AND DISCUSSION
The electronic absorption spectra of the (Cl)MnTPP
and (AcO)MnTPP complexes correspond to those
described in [7], where the structures of the complexes
were confirmed by physicochemical methods (elec-
tronic and IR spectroscopy).
cH O interval from 0.1 to 0.5 mol/L. In the second
2
2
region, kapp is independent of cH O (Fig. 5). At H2O2
2
2
concentrations from 1.26 to 3.32 mol/L (third region),
the reaction order with respect to [H2O2] is –1/2 (Fig. 6).
The spectrophotometric study of the reaction of
(Cl)MnTPP with hydrogen peroxide revealed the fol-
lowing three intervals of peroxide concentrations:
0.017–0.5, 0.67–1.0, and 1.26–3.98 mol/L. Each inter-
val contains two isosbestic points at 620 and 730, 485
and 605, and 485 and 605 nm, respectively (Figs. 1–3).
With reference to published data [8–10], the final
products were identified as follows: an oxidized form
with electron-deficient localization on the aromatic
macrocycle (π-radical cation of manganese(III) tet-
raphenylporphine) (679 nm) in the first concentration
interval (Fig. 1, curve 5) and a form oxidized at the
Mn atom (manganese(IV) tetraphenylporphine) (broad
band at 520–550 nm) at higher peroxide concentrations
(Figs. 2, 3; curves 5). In the first and third regions of
H2O2 concentrations, the initial spectrum corresponds
467
A
1
550
520
5
to (Cl)MnIIITPP (Figs. 1, 3; curves 1). In the second
concentration interval, the electronic absorption
spectrum is a curve with absorption maxima of
(Cl)MnIIITPP (467 nm) and its π-radical cation
(679 nm) (Fig. 2, curve 1). In all cases, the first order
λ, nm
III
Fig. 3. Electronic absorption spectra of (Cl)Mn TPP during
the reaction with H O at 298 K and c = 2.52 mol/L.
2
2
H2O2
For designations, see Fig. 1.
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 51 No. 11 2006

1822
ln(c0/cτ)
LOMOVA et al.
Here, kv1 and kv3 are the true rate constants for the reac-
tion with hydrogen peroxide for the first and third H2O2
concentration intervals, respectively.
Taking into account the data in Figs. 1–3, we may
propose the following scheme of elementary steps for
the overall reaction described by rate equation (4):
1
2
3
1.0
0.8
0.6
0.4
0.2
4
5
k
1
(Cl)MnIIITPP + H2O2
(Cl)(H2O2)MnIIITPP
(Cl)(H2O2)MnIIITPP, (6)
O=MnIII(TPP+•)
k
2
(7)
+ H2O + Cl–.
6
The rate equation for irreversible step (7) is
–dc(Cl)(H O )MnIII /dτ = k2c
.
(Cl)(H2O2)MnIIITPP
(8)
TPP
2
2
With allowance for equilibrium (6), we may write
0
100
200
300
τ, s
–dc(Cl)(H O )MnIIITPP/dτ = –dc(Cl)MnIIITPP/dτ
2
2
(9)
III
Fig. 4. Plot of ln c /c vs. τ for the reaction of (Cl)Mn TPP
with H O at c
0
τ
= k2K1c(Cl)MnIIITPPcH O
.
2
2
–5
= 2 × 10 mol/L, cH O = (1, 3)
2 2
(Cl)MnIIITPP
2
2
A comparison of Eqs. (4) and (9) gives kv1 = k2K1.
2.26, (2, 4) 1.0, and (5, 6) 0.017 mol/L, and T = (1, 5) 308,
(2, 4, 6) 298, and (3) 293 K. Goodness of fit for straight lines
is R = 0.99.
To verify the adequacy of the scheme of Eqs. (6) and
(7), a solution of (Cl)MnIIITPP in DMF was spectro-
photometrically titrated with hydrogen peroxide
(Fig. 7). The titration curve contains one step. A linear
correlation is observed between the logarithm of the
ratio of the equilibrium concentration of the product of
reaction (6) to the equilibrium concentration of the
starting complex (Cl)MnIIITPP (indicator ratio I) and
the logarithm of the concentration of hydrogen perox-
ide. The slope ratio of the straight line to the abscissa is
close to unity (Fig. 7), which means that one molecule of
2
These results make it possible to write the experimen-
tally determined overall rate equations for regions of
H2O2 concentrations of 0.017–0.1 and 1.26−3.32
mol/L:
–dc(Cl)MnIII /dτ = kv1c(Cl)MnIIITPPcH O
,
.
(4)
(5)
2
2
TPP
–1/2
–dc(Cl)MnIII /dτ = kv3c(Cl)MnIIITPP
c
H2O2
TPP
–1
–logk [s ]
app
4
–1
k
× 10 , s
1
2
app
1
2.3
2.1
1.9
1.7
1.5
1.3
120
100
80
3
60
2
40
3
20
0
0.1
0.2
0.3
logc
0.4
0.5
[mol/L]
0
0.02 0.04 0.06 0.08 cH O , mol/L
2 2
H O
2
2
Fig. 6. Plot of –logkapp vs. cH O for the reaction of
Fig. 5. Apparent rate constant of the reaction of
2
2
II-I
III
(Cl)Mn TPP with H O vs. H O concentration at T = (1)
(Cl)Mn TPP with H O in the H O concentration interval
2 2 2 2
2
2
2
2
2
1.26–3.32 mol/L at T = (1) 308, (2) 298, and (3) 288. Goodness
308, (2) 298, and (3) 288 K. Goodness of fit is R = (1,2)
0.99 and (3) 0.98.
2
of fit for straight lines is R = (1) 0.91, (2) 0.94, and (3) 0.92.
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 51 No. 11 2006

KINETICS AND MECHANISM OF OXIDATION OF MANGANESE(III)
1823
Table 1. Apparent rate constants of the reaction of
hydrogen peroxide is involved in reaction (6). The con-
centration equilibrium constant of reaction (6) at 298 K
calculated using formula (3) is K1 = (20 3) L/mol.
Thus, the rate constant of elementary reaction (7) at
298 K, which is equal to kv1/K1, is 1.95 × 10–3 s–1.
(Cl)MnTPP with H2O2
kapp × 104, s–1
cH O
,
2
2
mol/L
288 K
293 K
298 K
308 K
The (Cl)(H2O2)MnIIITPP complex with the H2O2
First reacting series
0.017
4.3 0.1
7.9 0.1
15.1 0.8
19.1 0.6
28.5 2.0
10.3 0.1
19.5 0.4
35.9 0.6
49.1 0.7
25
48
87 4.5
123
148
171
1
2
molecule coordinated to the sixth coordination site is
not accumulated in the reaction mixture, because its 0.033
equilibrium concentration is low due to the low concen-
tration of ç2O2, and the complex is oxidized at the mac-
rocycle according to Eq. (7) (Fig. 1).
For the third interval of H2O2 concentrations, the
reaction scheme is more complicated:
0.068
0.1
0.2
0.34
0.5
4
8
9
7
66
81
3
6
6
34
2
68 2.5
122
221.5
K
1
Second reacting series
H2O2
H+ + HO–2 ,
(10)
0.67
0.81
0.91
1.00
68
68
67 4.5
62
3
3
126
127.5
119
7
3
5
227
227 12
209
9
(Cl)MnIIITPP + HO–2
(Cl)(HO–2 )MnIIITPP (11)
k
2
8
rapidly
3
120 6.5 224.5 18
Third reacting series
K
(Cl)(HO–2)MnIIITPP
(Cl)O
3
= MnIV(TPP+•)+ OH–,
1.26
1.51
1.76
2.26
2.52
3.32
3.98
61 3.5
119
103
100
94
78
70
4
4
228 16
(12)
58
54
52.5
42
3
3
2
2
1
197
197
188
4
4
4
3
4
2
1
1
(Cl)O=MnIV(TPP+•) + HO–2
= MnIVTPP + HCl + O2 slowly,
O
k
4
69
60
51
2
3
1
1
165 6.5
(13)
(14)
37
142
143
6
9
K
5
éç– + H2O2
HO–2 + H2O.
32.8 0.4 48.5
68
The first step involving (Cl)MnIIITPP (11), like
step (6), proceeds rapidly and irreversibly at high H2O2
In fact, the rate equation derived for the presented
scheme of reactions (10)–(14) validates the above as-
sumptions. The presence of chlorine in the coordination
sphere of the manganese porphyrin at the step of the
coordination of hydrogen peroxide in any form (Eqs.
(6), (11)) is confirmed by the specially performed com-
parison with the (AcO)MnIIITPP complex. The corre-
sponding data are displayed in Table 2; they show that
the reaction rate depends strongly on the nature of the
acido ligand.
concentrations. Peroxide is coordinated as HO–2 but
due to the donor–acceptor bond. Then, two electrons
are transferred from the easily polarized porphyrin
macrocycle and manganese cation to the coordinated
peroxide to establish equilibrium (12). The attack of
HO–2 , which was formed during acquisition of equilib-
riums (11) and (14), on the coordination site of the rad-
ical-cation manganese(IV) complex favors slow trans-
formation according to Eq. (13). Gas evolution is not
observed in the experiment because of the low concen-
tration of manganese porphyrin in the form of (ël)O =
The rate equation for rate-determining step (13) has
the form
.
MnIV(TPP+ ); nascent é2 is most likely in the solution.
.
.
–dc(Cl)O=Mn
)/dτ = k4c(Cl)O=MnIV(TPP+ )cHO–. (15)
IV(TPP+
2
Thus, in the proposed scheme of reactions (10)–
(14) the laws of the reactions are different than for
Eqs. (6) and (7), because the hydrogen peroxide concen-
.
Let us write the concentrations c(Cl)O=Mn
and
)
IV(TPP+
cHO– taking into account the scheme of reactions (10)−(14).
tration increases and the perhydroxyl ion HO–2 appears
2
After the (Cl)O = MnIV(TPP+ ) concentration was suc-
.
in kinetically significant amounts. The metal porphyrin
coordinates hydrogen peroxide as HO–2 . It is most likely
that the elimination of éç– from coordinated HO–2
instead of ç2é (Eqs. (12), (7)) results in the situation
cessively expressed through the equilibrium constants
K3, K5, and K1, we obtain the equation
III
.
c(Cl)O=Mn
= K3c(Cl)Mn TPPcO–1H–
IV(TPP+
)
that Cl– remains in the coordination sphere of the result-
–2
HO2
.
ing MnIV π-radical cation MnIV−(ël)O=MnIV(TPP+ ).
III
(16)
= K3c(Cl)Mn TPPK5c
Since evolved éç– is in a medium with a large amount
–1
H2O
= K3c(Cl)MnIIITPPK5c
of ç2é2, equilibrium (14) should be taken into account.
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 51 No. 11 2006

1824
LOMOVA et al.
/dτ = k4K3c(Cl)Mn TPPK5K1–1
A
(‡)
III
–dc(Cl)O=Mn
IV(TPP+•
)
(18)
× c
K11/2
c
= constc(Cl)Mn
c
–1
H2O2
1/2
H2O2
–1/2
.
H2O2
III
TPP
0.8
0.4
Equation (18) agrees with experimentally deter-
mined Eq. (5). Thus, kv3 = k4K3K5 K–J1/2 . The numerical
value of K1 is known: 2.4 ×10–2 at 298 K [11].
The kv1 and kv3 numerical values found by the opti-
mization of the plots presented in Figs. 5 and 6 are
listed in Table 3.
0
0.2
0.4
cH O , mol/L
0.6
2
2
Starting from the data obtained, we may write the
overall scheme for the reaction of (Cl)MnTPP with H2O2
at all studied concentrations of the latter (Scheme 1). At
low H2O2 concentrations, the reaction rate is controlled
by the step of two-electron oxidation of manganese por-
phyrin and the reduction of H2O2 on the metal in
logI
(b)
1.0
0.6
0.2
'
(Cl)(H2O2)MnTPP (k2 ). At high H2O2 concentrations,
the reaction rate is controlled by the step of two-electron
1.0
0.5
–0.2
.
reduction of the (Cl)O = MnIV(TPP+ ) π-radical cation
–
IV
–
logcH O [mol/L]
'
to O=Mn TPP and Cl and oxidation of HO2 (k3 ) with
2
2
the evolution of é2 and H+.
Fig. 7. (a) Titration curve and (b) the plot of logI vs.
Under an excess of H2O2, the O=MnIVTPP complex
oxidized at the central manganese atom is stable in
solution over time.
2
III
logcH O (R = 0.98) for the titration of the (Cl)Mn TPP
2
2
complex in DMF with hydrogen peroxide.
As already mentioned, we failed to determine exper-
imentally the overall kinetic equation at intermediate
H2O2 concentrations (Table 1). The data in Fig. 2 show
After the HO–2 concentration was expressed from
Eq. (10), we have the equation
that the final product O=MnIVTPP is formed under the
reaction conditions from both the starting (Cl)MnIIITPP
1/2
H2O2
cHO– = K11/2
c
.
(17)
2
.
and (Cl)O=MnIV(TPP+ ) complexes. The isosbestic
Both these values are inserted into Eq. (15) to obtain
point on the right descent of the charge-transfer band of
(Cl)MnIIITPP (467 nm) is distorted in the very begin-
ning of the process. A similar point at λ = 605 nm
Cl
.
belongs to the transition (Cl)O= MnIV(TPP+ )
N
N
O=MnIVTPP, and spectrum 1 passes through this point,
.
k2
Mn
O=MnIII(TPP+ )
–H2O, –Cl–
most likely, occasionally.
N
O
N
'
The reaction of the oxidation of manganese(III) por-
phyrin with hydrogen peroxide is very sensitive to the
nature of the acido ligand in the composition of the
mixed-ligand acidoporphyrin complex. The acetate
complex (AcO)MnIIITPP reacts with H2O2 much more
K1
+H2O2
H
O
H
(Cl)MNIIITPP
Cl
+HO–2
rapidly than the chloride complex (Cl)MnIIITPP
k'1
N
N
'
K2
(Tables 1, 2). The rate of formation of the
.
(Cl)O=MnIV(TPP+
Mn
O–
)
–OH–
.
O=MnIII(TPP+ ) π-radical cation can be measured
N
k'3
N
+HO–2
–O2, –HCl
spectrophotometrically in the interval cH O = 0.013–
2
2
O
O=MnIVTPP
0.511 mol/L. Already at cH O = 1.0 mol/L, the reaction
H
2
occurs instantly, and th2e reaction product is
O=MnIVTPP. For low cH O (0.013–0.052 mol/L), the
2
2
order of this reaction with respect to [H2O2] is close to
unity (0.72), which indicates that its mechanism is
common to that of (Cl)MnIIITPP (Scheme 1, route
Scheme 1. Overall scheme of the reaction of (Cl)MnTPP
with H O .
2
2
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 51 No. 11 2006

KINETICS AND MECHANISM OF OXIDATION OF MANGANESE(III)
1825
Table 2. Apparent rate constants of the reaction of Table 3. True rate constants, E, and ∆S≠ of the reaction of
(AcO)MnTPP with H2O2
(Cl)MnTPP with H2O2
kapp × 104, s–1
Interval
cH O
,
2
kv× 102,*
E,
∆S≠,
2
of cH O
,
T, K
mol/L
2
2
288 K
298 K
308 K
L/(mol s)
kJ/mol
J/(mol K)
mol/l
0.013
0.026
0.039
0.052
0.078
0.104
0.13
12.5 0.1
26
46
57
1
1
3
53
93
111
147
161
176
2
0.017–0.10 288
1.41
3.90
9.45
0.72
1.34
2.51
70
46
1
–44
3
22
27
33
1
1
1
2
4
3
8
298
308
1.26–3.32 288
298
72 1.5
1
–133
3
39.5
84
91
3
1
5
43.6 0.6
9
47
61
62
1
2
2
94.1 0.9
185 10
241
308
0.26
0.52
121
136
5
2
3
* k and k for c
intervals of 0.017–0.10 and 1.26–3.32 mol/L,
v1
v3
H2O2
respectively.
Institutions (RNP2.2.1.1. 7181)”, by the Russian Sci-
ence Support Foundation (2005), and by the DAAD
Program “Mikhail Lomonosov 2005.”
'
'
k2 ). For cH O > 0.5 mol/L, a lower reaction
2 2
K1
order with respect to [H2O2] is observed. In the case of
(AcO)MnIIITPP, the increase in the reactivity may be
explained only by the fact that the AcO– acido ligand is
more strongly bonded than Cl–. Evidently, in a
DMF−H2O medium where the reaction occurs, the DMF
molecule coordinated to the sixth coordination site is
substituted in the initial complex when H2O2 is coordi-
nated. Due to the Chernyaev trans influence, DMF is
more easily substituted in the (AcO)MnIIITPP complex
than in (Cl)MnIIITPP. In addition, due to the possibility
of transferring electronic effects of the acido ligands
through a transition metal with its partially filled d shell
to the macrocycle, the latter donates an electron more
easily than (Cl)MnIIITPP does to form the π-radical cat-
ion in (AcO)MnIIITPP.
REFERENCES
1. O. V. Cheremenskaya, A. B. Solov’eva, G. V. Pono-
marev, and S. F. Timashev, Zh. Fiz. Khim. 75 (10), 1787
(2001) [Russ. J. Phys. Chem. 75 (10), 1633 (2001)].
2. O. A. Golubchikov and B. D. Berezin, Usp. Khim. 55
(8), 1361 (1986).
3. B. D. Berezin and G. V. Sennikova, Kinet. Katal. 9 (3),
528 (1968).
4. B. D. Berezin and G. V. Sennikova, Zh. Fiz. Khim. 43
(10), 2499 (1969).
5. A. D. Adler, F. R. Longo, F. Kampas, and J. Kim,
J. Inorg. Nucl. Chem. 32, 2443 (1970).
6. T. N. Lomova, Doctoral Dissertation in Chemistry
(IKhNR RAN, Ivanovo).
According to [12], the manganese(III) porphyrins
under study possess catalase activity in an alkaline
medium. The results presented above show the easy
formation of oxidized forms of the complexes and no
destruction of the macrocycle upon the interaction with
H2O2. Due to this, manganese(III) porphyrins are very
promising for use as models of natural catalases.
7. T. N. Lomova, N. I. Volkova, and B. D. Berezin, Zh.
Neorg. Khim. 30 (4), 935 (1985).
8. L. Kaustov, M. E. Tal, A. I. Shames, and Z. Gross, Inorg.
Chem. 36 (16), 3503 (1997).
9. N. Carnieri, A. Harriman, G. Porter, and K. Kalyana-
sundaram, J. Chem. Soc., Dalton Trans., 1231 (1982).
10. H. Volz and W. Müller, Chem. Ber. Recueil. 130, 1099
(1997).
ACKNOWLEDGMENTS
11. W. Schumb, C. Satterfield, and R. Wentworth, Hydrogen
Peroxide (Rheinhold, NewYork, 1955; Inostrannaya Lit-
eratura, Moscow, 1958).
12. M. V. Klyuev, M. E. Klyueva, E. N. Kiseleva, et al., Pro-
ceedings of VI Russia Conference “Mechanisms of Cat-
alytic Reactions,” Moscow, 2002 (Novosibirsk, 2002),
vol. 2, p. 180.
This work was supported in part by the Program for
Basic Research of the Russian Academy of Sciences
(no. 8 “Directed Synthesis of Substances with Specified
Properties and Design of Related Functional Materi-
als”), by the Analytical Tagerted Program “The Devel-
opment of the Scientific Potential of Higher Education
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 51 No. 11 2006