ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Radical cations from 4,4'-methylenediphenols.  Intermediary products of electron-transfer indicated by the epr method

L. Omelka and A. Tkáč

Department of Physical Chemistry, Faculty of Chemical Technology, Slovak Technical University, CS-81237 Bratislava

Abstract: Differently substituted 4,4'-methylenediphenols I donate an electron to the AlCl₂⁺ electron acceptor in the AlCl₃-CH₃NO₂-benzene solution at laboratory temperature to give radical cations II of different stability. The symmetrical distribution of spin density in individual phenyl rings remains preserved. Nevertheless, an asymmetrical redistribution to equivalent positions (ortho, meta) in each of these rings take place owing to steric distortion in the process of formation of the ion-radical complex. The effect of voluminous substituents in ortho positions on stability of the primary complex of ion-radical with the AlCl₄^- counterion is discussed. This complex is subjected to fragmentation and subsequently gives rise to radical cations from 4,4'-biphenyldiols.

Full paper in Portable Document Format: 452a247.pdf

Chemical Papers 45 (2) 247–255 (1991)