The possibility of excess electron binding of a series of (bi) cyclic, ring-constrained disulfides, in gas phase was investigated by ab initio MP2/6-31+G** calculations. It is shown that ring strain favors electron attachment, as neutral compounds are very sensitive to angular and dihedral compressions: cyclic disulfides will preferentially undergo a spontaneous electron capture compared to linear analogs, with superior positive values for adiabatic electron affinity. Cyclisation effect is progressively switched off for higher-member rings, but remains important for disulfides grafted on molecular bridges. Its structural consequences are analysed, with different behaviors for neutral and radical anionic moities. (c) 2008 Elsevier B.V. All rights reserved.