Scheme 4 Oxidation processes electrochemically triggered for the described oxygen carrier sytems.
connection with the dinitrogen reactivity, the corresponding 5
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although the percentage of dinitrogen-adduct is not as satis-
factory as for compound 1, probably due to the donating
inductive effect of the methyl and methoxy groups.
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V. G. Young, Jr, L. Que, Jr, A. D. Zuberuhler and W. B. Tolman,
¨
Finally, cyclic voltammetry experiments performed for all
synthesized sHo–o-adducts reveal that the oxygen is reversibly
bonded, thus being possible to remove it upon oxidation of the
adduct (Table 1, Fig. 1). In addition, after exhaustive electro-
lysis of their corresponding sHo–o-adducts at +1.20 V for all
the synthetic strategies described above, the initial reactant 1,
TNT and TNA, is recovered in a 100% yield. Thus, as
illustrated in Scheme 4, the reversible binding/removing of
the dioxygen by an external electrochemical stimulus of those
oxygen synthetic trapping systems is well-established.
Science, 1996, 271, 1397; (b) G. A. Abakumov, A. I. Poddel’sky,
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Conclusions
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¨
93, 605.
¨
R. Nader and A. de Meijere, Angew. Chem., Int. Ed. Engl., 1981,
In summary, the present investigation describes a new syn-
thetic family of complexes which are able to reversibly bind
and remove dioxygen after an external redox stimulus invol-
ving either chemical or electrochemical electron transfer;
showing their potential application as oxygen carriers. The
fact that they can bind oxygen makes these systems particu-
larly attractive for several applications such as devices, sensors
or even synthetic carrier models of dioxygen complexes.
9. D. P. Curran, in Comprehensive Organic Synthesis, ed. B. M.
Trost and I Fleming, Pergamon Press, Oxford, 1984, vol. 14,
p. 715.
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´
D. H. Evans, J. Electroanal. Chem., 2007, 600, 294.
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13. (a) Switching can be repeated more than 250 times13b,c
;
Acknowledgements
(b) R. Rathore, P. Le Magueres, S. V. Lindeman and
J. K. Kochi, Angew. Chem., 2000, 112, 818; (c) R. Rathore,
P. Le Magueres, S. V. Lindeman and J. K. Kochi, Angew. Chem.,
Int. Ed., 2000, 39, 809.
We gratefully acknowledge financial support by the Ministerio
de Educacion y Ciencia of Spain through projects BQU 2003-
´
05457 and CTQ2006-01040. The authors are pleased to ac-
knowledge Professors C. P. Andrieux and J. Pinson from the
University Paris 7 for spectroelectrochemical measurements
and helpful discussions.
14. (a) It has been published that the oxidation potential of dianionic
s adduct complexes14b are two electron oxidation processes in
which the peak potential values are in the range of 1.00–1.20 V vs.
SCE; (b) I. Gallardo, G. Guirado and J. Marquet, J. Electroanal.
Chem., 2000, 488, 64.
15. M. C. Buzzeo, O. V. Klymenko, J. D. Wadhawan, C. Hardacre,
K. R. Seddon and R. G. Compton, J. Phys. Chem. A, 2003, 107,
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