G. Farnia et al., ELECTROCHEMICAL-BEHAVIOR OF 1,2-DIHYDROXYCYCLOBUTEN-3,4-DIONE IN DIMETHYL FORMAMIDE, Journal of electroanalytical chemistry [1992], 348(1-2), 1993, pp. 339-354
The electrochemical behaviour of 1,2-dihydroxycyclobuten-3,4-dione (sq
uaric acid, H2SQ) in dimethylformamide was investigated. On a Pt elect
rode, the reduction involves two successive, chemically reversible, on
e-electron processes, affording hydrogen and the basic species HSQ- an
d SQ2- respectively. The oxidation of SQ2- thus formed occurs in two c
onsecutive, chemically reversible, one-electron steps, affording the r
adical anion SQ.- and the neutral species SQ-degrees; the neutral spec
ies SQ-degrees is stable in the time-scale of the voltammetric experim
ents only. In contrast, the chemically irreversible oxidations of H2SQ
and HSQ- appear as more complicated processes. The oxidation of hydro
gen in the presence of the electrogenerated basic species was also stu
died. A comparison with the results obtained on an Hg electrode is mad
e and the occurrence of a different voltammetric behaviour, as regards
the reduction process, is discussed briefly.