Bicyclic disulfide derivatives of isocyanuric acid-methyl, phenyl and 2-(2-methoxy-phenoxy)ethyl N-substituted derivatives of 8,9-dithia triaza-bicyclo[14.3.1]eicosane and 7,8-dithia triaza-bicyclo[12.3.1]octadecane and 18-methyl-5lambda(4) 8(lambda)4,9,12-tetrathia-1,16,18-triaza-tricyclo [14.3.1.0(5.8)]eicosane-17,19,20-trion were studied by cyclic voltammetry and PM3 level molecular modeling. The oxidation involves an electrochemically reversible electron transfer followed by fast potential-determining reaction of second kinetic order and a relatively slow current-determining reaction of first-order (k = 0.33-32.7s(-1)). Molecular modeling has shown three different types of HOMOs in this reaction series and consequently different oxidation mechanisms. None of the frontier orbitals (HOMO and LUMO) is localized on the isocyanurate heterocycle so it does not intervene directly in redox transformations but it may participate in the stabilization of the positive charge in electrogenerated cation radicals by trans-annular interaction. (C) 2003 Elsevier Ltd. All rights reserved.