Several phenols with structures similar to vitamin E were oxidised and the intermediate species produced were characterised by in situ infrared and UV-vis spectroscopies The Fourier transform infrared (FIR) measurements were performed by chemically oxidising the phenols with 2 mol equiv of NO+SbF6- in CH3CN and recording the spectra between 1900 and 1300 cm(-1) with an attenuated total reflectance (ATR) probe utilising a fiber conduit and a diamond composite sensor The compounds that formed long-lived phenoxonium cations displayed two IR absorbances at 1665 (+/-15) cm(-1) and one at 1600 (+/-10) cm(-1) associated with the carbonyl symmetric ring stretch and asymmetric ring stretch modes The paraquinones are one of the long-term products of oxidation of the phenols and displayed solution phase IR absorbances at 1650 (+/-10) cm(-1) In situ electrochemical UV-vis experiments performed during the oxidation of the phenols led to the detection of bands due to the phenoxonium canons at 295 (+/-5) and 440 (+/-15) nm and due to the para-quinones at 260 (+/-10) nm The concentration of the substrate and the water content of the solvent had a major effect on the yields of the intermediates and products that were produced during the oxidation reactions (C) 2010 Elsevier Ltd All rights reserved