Measurements of the total and of the mass selected anion currents arising from electron attachment in gas-phase (CH3)(3)Si-NSN-Si(CH3)(3), precursor of the (SN)(x) polymer, are reported as a function of the impinging electron energy in the 0-6 eV energy range. Abundant production of long-lived molecular anions and of negative fragments at zero energy is associated with the formation of a (vibrationally excited) stable pi* anion state. In agreement, B3LYP/6-311G* calculations predict a positive (0.49 eV) vertical electron affinity. Electron attachment into the pi* LUMO at zero energy and into the lowest empty sigma* orbitals around 3.1 eV decays along dissociative channels which involve cleavage of the S-N bond, indicating that the small thiazyl chain is prone to dissociation upon electron addition.