Electrolysis of 2-methyl-1,4-naphthoquinone and 3,5-di-tert-butyl-1,2-benzoquinone using the flow-cell system with a column electrode

In order to clarify the features of the electrolysis, with the column elect rode of carbon fibers packing a porous Vycol(R) glass cylinder for the elec trolysis, of an organic compound producing an unstable product, electrolysi s of quinones was performed with the column electrode system. 2-Methyl-1,4- naphthoquinone (VK3) was used as a representative quinone producing a relat ively stable product, and 3,5-di-tert-butyl-1,2-benzoquinone (DBBQ) was use d as a quinone producing an unstable product. From the electric charge calc ulated from the area under the current-time curve, the number of electrons participating in electrolysis (n) was estimated to be 2. The n value was ea sily calculated in such a short electrolysis time as 30 s and with such a s mall amount of sample as 1 nmol. The electrolytic products were observed wi th a multiwavelength UV-Vis spectrophotometer. Thus, the proceeding of the electrolysis can easily be monitored. The electrolysis of DBBQ in carrier s olutions with and without supporting electrolyte was performed. Using the c olumn electrode, the electrolytic product of DBBQ with a supporting electro lyte-free carrier solution was collected, and its nuclear magnetic resonanc e (NMR) and mass spectra could be obtained, in which analytical methods a s alt-free condition is desired. (C) 2000 Elsevier Science Ltd. All rights re served.