ESR study of intermediates in electroreduction of 3-hexyne-2,5-diol

The intermediates of electroreduction of 3-hexyne-2, 5-diol at platinized p latinum electrode in perchlorate aqueous solutions with various pH values h ave been studied by using electrochemical-ESR technique with the spin trap phenyl tert-butyl nitrone. The six-line spectra in the three solutions with 1. 5, 3. 5 and 5. 0 pH values could be ascribed to the form of the radical s, such as CH3C HC=CCH2CH3 , in the process of producing 3-hexyne, The four -line spectra, increasing in their intensities with increase in pH values f rom 1. 5 to 5. 0, show that a 2-hydroxyalkyl radical CH3C (OH)CH=CHCH(OH)CH 3 is formed via the interaction between the atom H and intermediates 3-hexe ne-2, 5-diol and/or CH3C(=O) . CH=CHCH(OH)CH3.