Primary steps of oxidation and electronic interactions in anodic cleavage of α,ω-diisocyanurate substituted dialkyl disulfides

The electrochemical oxidation of 1, 1'-bis(3,5-dimethyl- [1,3,5] triazinane-2,4,6-trionyl)-alpha,alpha'-diorganyl-omega,omega'-disulfides involves a fast electron transfer followed by two chemical steps according to a ECC scheme. Using MM+, PM3 and ab initio SCF/3-21G* molecular modeling it was shown that the low oxidation potential and the smallest current-determining cleavage rate constant in the reaction series of the disulfide with (CH2)(6) spacerbetween S-S bridge and the terminal heterocycles is due to an interaction of the pi-components of the highest filled orbitals of the two heterocycles (HOMO and HOMO-1) with the LUMO (n-orbital of S) of the cation radical. (C) 2004 Elsevier Ltd. All rights reserved.