Res. Chem. Intermed.
, Vol. 32, No. 2, pp. 137–144 (2006)
Also available online - www.vsppub.com
Radical cations of 1,4-dialkoxybenzenes and alkyl
1,4-dialkoxybenzenes generated through one-electron
oxidation by perﬂuorodiacyl peroxides
, HONG-YAN DOU
, YUE-FA GONG
and CHENG-XUE ZHAO
College of Chemistry and Chemical Engineering, Shanghai Jiaotong University,
Shanghai 200240, China
Department of Chemistry, Huazhong University of Science and Technology, Wuhan 430074, China
Received 31 January 2005; accepted 18 July 2005
Abstract—Radical cations of 1,4-dialkoxybenzenes 1 and 2 and alkyl 1,4-dialkoxybenzenes
3–9 generated in oxidation of the parent donors by perﬂuorodi[1-(2-ﬂuorosulfonyl)ethoxy]propio-
nyl peroxide 10 at –40
C and pentaﬂuorobenzoyl peroxide 11 at 15
C were observed by ESR.
Radical cation 6
, generated in other oxidation systems, i.e., Ce(SO
/HOAc, has also been investigated. Based on ESR observation and products analysis,
an electron-transfer mechanism of the oxidation reaction is proposed and the inﬂuencing factors on
hyperﬁne splitting constants of the radical cations are discussed.
Keywords: ESR; dialkoxybenzene radical cations; perﬂuorodiacyl peroxide; one-electron oxidation.
The chemistry of radical cations has been developed greatly in recent years
because of the numerous novel synthetic methods involving the participation of
aromatic radical cations as intermediates. Many radical cations of electron-rich
aromatics, including alkoxybenzenes, have been generated in their oxidation by
phenyliodine(III) bis(triﬂuoroacetate) (PIFA): potassium 12-tungstocobalt(III)ate,
; 9,10-dicyanoanthracene (DCA) and AgNO
[1–5] and some of
their radical cations have been characterized by ESR and visible spectroscopy .
The oxidation of some dimethoxybenzenes (1, 4–6) with perﬂuorodiacyl peroxides
under mild conditions has been carried out in our group since 1983 [7–11], and
To whom correspondence should be addressed. Tel.: (86-21) 5474-3263, ext. 804. Fax: (86-21)
5474-1297. E-mail: firstname.lastname@example.org