ESR study of alumotrioxide
Russ.Chem.Bull., Int.Ed., Vol. 51, No. 4, April, 2002
643
recombination of the peroxy radicals from trioxide, it
forms in this case due to the molecular decomposition of
intermediate 4.
Spectral studies were performed at the Analytical Cenꢀ
ter of the G. A. Razuvaev Institute of the RAS and
financially supported by the Russian Foundation for Baꢀ
sic Research (Project No. 00ꢀ03ꢀ42004) and the Federal
Target Program "Integration" (No. 372/2001).
The authors thank G. A. Abakumov for interest in
the work and helpful discussion of the experimental
results.
0
.25 mT
H
t
t
Fig 5. ESR spectrum of the (Bu O) Al—Bu OOH (1 : 2) reacꢀ
tion mixture in ethylbenzene (isopropylbenzene) at 298 К in
the presence of PBN.
3
The HFC constants of the found adducts differ from
those of adduct 11 and are close to those for adduct 10.
However, the absence of HFC of the radicals studied,
unlike the situation for radical 5, allows us to assign
them to the PBN adducts with the peroxy radicals formed
from the oxidized substrates: 13 is formed from ethylꢀ
benzene and 14 is formed from isopropylbenzene.
References
1
2
3
4
. V. A. Dodonov, L. P. Stepovik, and S. M. Sofronova,
Zh. Obshch. Khim., 1990, 60, 1839 [J. Gen. Chem. USSR,
990, 60 (Engl. Transl.)].
. V. A. Dodonov, L. P. Stepovik, A. S. Soskova, and E. A.
Zaburdaeva, Zh. Obshch. Khim., 1994, 64, 1715 [Russ. J. Gen.
Chem., 1994, 64 (Engl. Transl.)].
. V. A. Dodonov, L. P. Stepovik, and E. A. Zaburdaeva,
Zh. Obshch. Khim., 1997, 67, 116 [Russ. J. Gen. Chem.,
1
1
997, 67 (Engl. Transl.)].
. V. A. Dodonov, E. A. Zaburdaeva, N. V. Dolganova, L. P.
Stepovik, and T. I. Zinov´eva, Zh. Obshch. Khim., 1997,
This assumption was confirmed by the decomposiꢀ
tion of diꢀtertꢀbutyl peroxalate in ethylbenzene in the
presence of hydroperoxide 2 and PBN without removal
of the air oxygen. The ESR spectrum for this mixture
6
7, 988 [Russ. J. Gen. Chem., 1997, 67 (Engl. Transl.)].
5. I. M. Martynova, L. P. Stepovik, and V. A. Dodonov,
Zh. Obshch. Khim., 2001, 71, 785 [Russ. J. Gen. Chem.,
2
001, 71 (Engl. Transl.)].
6
7
8
9
. L. P. Stepovik, E. A. Zaburdaeva, and V. A. Dodonov,
Zh. Obshch. Khim., 1997, 67, 282 [Russ. J. Gen. Chem.,
represents a triplet of doublets with aN = 1.351 and aH
.102 mT.
Published data concerning the stability of the adꢀ
=
0
1
997, 67 (Engl. Transl.)].
. E. A. Zaburdaeva, L. P. Stepovik, V. A. Dodonov, and
I. M. Martynova, Zh. Obshch. Khim., 1997, 67, 2015 [Russ.
J. Gen. Chem., 1997, 67 (Engl. Transl.)].
. L. P. Stepovik, I. M. Martynova, and V. A. Dodonov,
Zh. Obshch. Khim., 1999, 69, 267 [Russ. J. Gen. Chem.,
1999, 69 (Engl. Transl.)].
ducts of peroxy radicals with PBN and their subsequent
transformations are contradictory. In the opinion of the
authors,1
8,26,27
the PBN adducts with peroxy radicals are
unstable at temperatures >250—260 К and transformed
3
3
into alkoxyl adducts. The authors assert that similar
adducts are stable at ∼20 °C but in the dark. The PBN
adducts detected by us at ∼20 °C should be attributed to
peroxy radicals based on the HFC parameters and pubꢀ
lished data.
. P. D. Bartlett and P. Günter, J. Am. Chem. Soc, 1966,
8
8, 3288.
0. N. A. Milas and B. Plesnièar, J. Am. Chem. Soc, 1983,
05, 1498.
1
1
1
1. S. L. Khursan, V. V. Shereshovets, A. F. Khalizov, A. I.
Voloshin, V. D. Komissarov, and V. P. Kazakov, Izv. Akad.
Nauk, Ser. Khim., 1993, 2056 [Russ. Chem. Bull., 1993, 42,
No. 12 (Engl. Transl.)].
12. S. L. Khursan, A. F. Khalizov, and V. V. Shereshovets, Izv.
Akad. Nauk, Ser. Khim., 1997, 924 [Russ. Chem. Bull., 1997,
t
•
t
•
Thus, the presence of the (Bu O) AlOO , Bu O ,
2
t
•
t
•
(
Bu O) AlO , and Bu OO radicals confirms the formaꢀ
2
tion of diꢀtertꢀbutoxyꢀtertꢀbutyl alumotrioxide in the reꢀ
action of alcoxide 1 with hydroperoxide 2 (in a ratio of
1
: 2) and the homolytic decomposition of the latter. The
4
6, 884 (Engl. Transl.)].
radicals that formed initiate oxidation, which is proved
by the presence in the reaction mixture of alkylaryl and
the corresponding peroxy radicals from the oxidized subꢀ
strates. However, the main pathway of aluminumꢀconꢀ
taining trioxide transformation is its decomposition with
1
1
3. S. L. Khursan, V. V. Shereshovets, N. M. Shishlov, A. F.
Khalizov, and V. P. Komissarov, React. Kinet. Catal. Lett.,
1
994, 52, 249.
4. Yu. A. Alexandrov and B. I. Tarunin, J. Organomet. Chem.,
982, 238, 125.
1
8
0% O evolution (to 80%), and 50% of this amount are
2
15. Yu. A. Aleksandrov, N. G. Sheyanov, Zh. Obshch. Khim.,
1969, 39, 141 [J. Gen. Chem. USSR, 1969, 39 (Engl.
Transl.)].
in the singlet state. Note that, unlike organic dialkyl
trioxides, where singlet dioxygen is the product of the