R. Muller et al., THE ELECTROCHEMICAL OXIDATION OF 1,4-BIS(METHYLSELENO)BENZENE (SELENIUM ANALOG OF WURSTERS BLUE) IN ACETONITRILE, Journal of the Electrochemical Society, 145(2), 1998, pp. 541-548
Citations number
49
Categorie Soggetti
Electrochemistry,"Materials Science, Coatings & Films
The electrochemical oxidation of 1,4-bis(methylseleno)benzene (la) was
studied in acetonitrile by conventional and microelectrode techniques
. Using untreated acetonitrile (0.02% nominal water content)/0.10 M Na
ClO4, cyclic voltammetry showed two irreversible bielectronic oxidatio
n signals, corresponding to the consecutive oxidation of both selenium
atoms into their selenoxides, as evidenced by controlled potential co
ulometry and electrolysis. In superdry acetonitrile/0.10 M tetra-n-but
ylammonium hexafluorophosphate (TBAPF(6)), the reversible oxidation of
la into its radical cation was observed. Semiempirical computations b
y the parametric method 3 (PM3) evidenced that the unusual stability o
f this species compared to radical cations of both alkylaryl-and diary
lselenides is due to the equal distribution of the positive charge on
both selenium atoms. Investigation of this first electron transfer and
the following process by cyclic voltammetry at various scan rates, te
mperatures, and concentrations, indicated that the radical cation of l
a dimerizes reversibly into a dication, which is according to PM3 comp
utations energetically favored by 368 kJ mol(-1). The dimeric dication
can be considered to be formed by two intermolecular two-center three
-electron Se-Se bonds.