Chemiluminescence in endoperoxide destruction
Russ.Chem.Bull., Int.Ed., Vol. 56, No. 2, February, 2007
209
1О2 generation that in solution triplet oxygen quenches
the dimol luminescence at λ = 700 nm. According to our
data on the endoperoxide decomposition (70 °С) on the
silica gel surface (0.125—0.160 mm, 600 m2 g–1), the toꢀ
tal chemiluminescence intensity at λ = 700 nm in an
oxygen atmosphere is by 1.2 times lower than that in
argon, whereas the ratio of the total IRꢀCL intensities of
singlet oxygen is virtually the same in O2 and argon.
Remarkably, for the MNEP decomposition on both
silica gel and alumina the ratios of the total intensities of
chemiluminescence arising in the IR spectral range and at
λ = 700 nm (taking into account the spectral sensitivity
of the FEU tube) differ insignificantly and range
within 460—590. For instance, when 1•10–4 mol g–1
endoperoxide decomposes on silica gel (0.125—0.160 mm,
600 m2 g–1) SIRꢀCL/Sλ=700 = 570 (70 °С), 590 (80 °С),
and 530 (90 °С), and for the MNEP concentration
equal to 5•10–4 mol g–1 on silica gel (0.160—0.200 mm,
600 m2 g–1) SIRꢀCL/Sλ=700 is 470 (70 °С). Similar
SIRꢀCL/Sλ=700 value (464) was obtained on acidic alumina
([MNEP] = 1•10–4 mol g–1, 80 °С). This fact additionꢀ
ally evidences that the light emitter at λ = 700 nm on
silica gel and Al2O3 has the single nature. The considerꢀ
ably lower CL intensity in the visible spectral range comꢀ
pared to the IRꢀCL intensity is caused by the very low
stationary concentration of (1О2)2, which is due to the
high constant of its dissociation (1010—1011 s–1).25—28
Nevertheless, singlet oxygen dimol is not, most likely,
the only emitter in the visible spectral range. Indeed, the
results presented above show that in the IR spectral reꢀ
tion of the endoperoxide on the sorbent surface obeys the
firstꢀorder law. The activation parameters of the process
determined show that the surface substantially catalyzes
the endoperoxide decomposition compared to the proꢀ
cess in solution. In addition to IRꢀCL, the endoperoxide
thermolysis is accompanied by chemiluminescence in the
visible spectral region. It is assumed that singlet oxygen
dimol (1О2)2 contributes substantially to the CL at λmax
=
630 and 700 nm.
This work was financially supported by the Russian
Foundation for Basic Research (Project No. 05ꢀ03ꢀ
32663a), the Council on Grants of the President of the
Russian Federation (Program of State Support for Leadꢀ
ing Scientific Schools of the Russian Federation, Grant
NShꢀ5486.2006.3), and the Division of Chemistry and
Materials Science of the Russian Academy of Sciences
(Program of Fundamental Research "Theoretical and Exꢀ
perimental Investigation of the Chemical Bond Nature
and Mechanisms of the Most Important Chemical Reacꢀ
tions and Processes").
References
1. W. Adam, D. V. Kazakov, and V. P. Kazakov, Chem. Rev.,
2005, 105, 3371.
2. C. Schweitzer and R. Schmidt, Chem. Rev., 2003, 103, 1685.
3. E. L. Clennan, Tetrahedron, 2000, 56, 9151.
4. K. Briviba and H. Sies, Method. Enzymol., 2000, 319, 222.
5. W. Adam and T. Wirth, Acc. Chem. Res., 1999, 32, 703.
6. A. A. Krasnovsky, Jr, Biologich. Membrany, 1998, 15, 530
[Membr. Cell Biol., 1998, 12, 665 (Engl. Transl.)].
7. J. M. Aubry, C. Pierlot, J. Rigaudy, and R. Schmidt, Acc.
Chem. Res., 2003, 36, 668.
1
gion DABCO on silica gel quenches the emission of О2,
which is a dimol precursor, by 2.7 times, whereas in the
visible spectral range at λ > 620 nm the CL is weakened
by 1.5 times only. Although DABCO completely quenches
8. C. Pierlot, J. M. Aubry, K. Briviba, H. Sies, and
P. Di Mascio, Method. Enzymol., 2000, 319, 3.
1
the IRꢀCL of О2 on Al2O3, the emission at λ > 600 nm,
nevertheless, is quenched incompletely. Evidently, the
luminescence spectrum at λ > 600 nm contains a compoꢀ
nent that is not related to (1О2)2. It is most likely that the
CL at λ < 560 nm is also caused not by singlet oxygen
dimol. Perhaps, it is caused by the decomposition of an
admixture of peroxides formed in the step of MNEP synꢀ
thesis and is not separated upon recrystallization. The
concentration of the admixture is probably very low, beꢀ
9. V. V. Shereshovets, S. L. Khursan, V. D. Komissarov, and
G. A. Tolstikov, Usp. Khim., 2001, 70, 123 [Russ. Chem.
Rev., 2001, 70, 105 (Engl. Transl.)].
10. G. L. Sharipov, V. P. Kazakov, and G. A. Tolstikov, Khimiya
i khemilyuminestsentsiya 1,2ꢀdioksetanov [Chemistry and
Chemiluminescence of 1,2ꢀDioxetanes], Nauka, Moscow,
1990, 288 pp. (in Russian).
11. H. H. Wasserman and D. L. Larsen, J. Chem. Soc., Chem.
Commun., 1972, 5, 253.
12. N. J. Turro, M.ꢀF. Chow, and J. Rigaudy, J. Am. Chem.
Soc., 1981, 103, 7218.
1
cause it is not detected by Н NMR. At the same time, it
cannot be ruled out that, unlike solution, the sorbent
surface provides other routes of endoperoxide decompoꢀ
sition in addition to the reaction shown in Scheme 2.
These routes are responsible for the chemiluminescence
observed at λ < 560 nm.
Thus, it is shown in the present work that the decomꢀ
position of 1,4ꢀdimethylnaphthalene endoperoxide supꢀ
ported on the silica gel or alumina surface is accompanied
by chemiluminescence in the IR and visible spectral reꢀ
gions. Singlet oxygen is the light emitter in the IR range.
It was found by the IRꢀCL method that the decomposiꢀ
13. A. Gordon and R. A. Ford, The Chemist’s Companion, Wiley,
New York, 1972, 541 pp.
14. M. J. Frisch, G. W. Trucks, H. B. Schlegel, G. E. Scuseria,
M. A. Robb, J. R. Cheeseman, V. G. Zakrzewski, J. A.
Montgomery, R. E. Stratmann, J. C. Burant, S. Dapprich,
J. Millam, M. A. D. Daniels, K. N. Kudin, M. C. Strain,
O. Farkas, J. Tomasi, V. Barone, M. Cossi, R. Cammi,
B. Mennucci, C. Pomelli, C. Adamo, S. Clifford,
J. Ochterski, G. A. Petersson, P. Y. Ayala, Q. Cui,
K. Morokuma, D. K. Malick, A. D. Rabuck,
K. Raghavachari, J. B. Foresman, J. Cioslowski, J. V. Ortiz,