This communication reports a novel process of the formation of elemental sulphur (S-o) that involves a specific electron transfer process (ETP) from a model organic sulphur compound thiourea. Solubility of CuCl in different systems were studied at 30 degrees C. Treatment of Cu+ as CuCl with naphthalene, an electron transfer agent taken in a protic solvent ethanol produces ion-radical i.e., naphthalenide anion. Formation of this ion-radical was proved by the solubility of copper in the absence and presence of naphthalene as well as by the absorption study at 30 degrees C. Increased solubility of copper in a system containing CuCl, naphthalene and thiourea in ethanol further proved the generation of ion-radical. Production of (S-o) in the temperature range of 30-40 degrees C suggested the cleavage of C-S bond present in the organic sulphur compound. The effect of reaction time revealed that the formation of S' was not continuous. Temperature had a profound influence on the formation of S') as substantial increase in the formation of S-o was observed for every 5 degrees C rise in temperature. The method succeeded in removing 66.4 mol% sulphur from thiourea as S-o at 6 h and 40 degrees C. Discontinuity in the formation of S-o inferred trapping of minor amount of it by the dissolved S2- ion leading to the formation of probably S-2(2-), the formation of which proceeded at a slow rate. Pseudo-first-order kinetic model was used to unfold the rates of formation of S-o. In the temperature range of 30-40 degrees C, intrinsic rate constant of S-o generation was found in the range of (8.3-40.6) x 10(-6) s(-1). The S-o formation process possessed an activation energy of 114.9 kJ mol(-1) and a preexponential factor of 5.8 x 10(14) s(-1). The way by which S-o was formed has a considerable relevance in the desulphurization of organic sulphur compound and the recovery of S-o from fossil fuels. (C) 2004 Elsevier B.V. All rights reserved.