The zwitterionic vinyliminium complex [Fe 2{μ-η 1:η 3-C(R′) C(S)C N(Me)(Xyl)}(μ-CO)(CO)(Cp) 2] ( 2a) (R′ = p-Me-C 6H 4 (Tol), Xyl = 2,6-Me 2C 6H 3) undergoes electrophilic addition at the S atom by HSO 3CF 3, MeSO 3CF 3, SiMe 3Cl, BrCH 2Ph, ICH 2CH CH 2 affording the complexes [Fe 2{μ-η 1:η 3-C(Tol) C(SX)C N(Me)(Xyl)}(μ-CO)(CO)(Cp) 2][Y] (X = H, Y = SO 3CF 3, 4a; X = Me, Y = SO 3CF 3, 4b; X = SiMe 3, Y = Cl, 4c; X = CH 2Ph, Y = Br, 4d; X = CH 2CH CH 2, Y = I, 4e). Compound 2a and the corresponding vinyliminium complexes 2b and 2c (R′ = CH 2OH, 2b; R′ = Me, 2c) react also with etherated BF 3 leading to the formation of the corresponding S-adducts [Fe 2{μ-η 1:η 3-C(R′) C(SBF 3)C N(Me)(Xyl)}(μ-CO)(CO)(Cp) 2] (R′ = Tol, 5a; R′ = CH 2OH, 5b; R′ = Me, 5c). In analogous reactions, the zwitterionic vinyliminium complexes undergo S-metalation upon treatment with in situ generated [Fp] +[SO 3CF 3] − [Fp = Fe(CO) 2(Cp)], leading to the formation of [Fe 2{μ-η 1:η 3-C(R′) C(S–Fp)C N(Me)(Xyl)}(μ-CO)(CO)(Cp) 2][SO 3CF 3](R′ = CH 2OH, 6a; R′ = Me, 6b; R′ = Bu n , 6c). Similarly, zwitterionic vinyliminium containing Se in the place of S also undergo Se-electrophilic addition. Thus, the complexes [Fe 2{μ-η 1:η 3-C(R′) C(SeX)C N(Me)(R)}(μ-CO)(CO)(Cp) 2][SO 3CF 3] (R = X = Me, R′ = Tol, 7a; R = Xyl, R′ = Me, X = Fp +, 7b) are obtained upon treatment of the neutral zwitterionic precursors with MeSO 3CF 3 and [Fp][SO 3CF 3], respectively. Alkylation at the S or Se atom of the bridging ligand is also accomplished by CH 2Cl 2, used as solvent, although the reaction is slower compared to more efficient alkylating reagents. The complexes formed by this route are [Fe 2{μ-η 1:η 3-C(R′) C(E-CH 2Cl)C N(Me)(R)}(μ-CO)(CO)(Cp) 2][X] [E = S, R = Xyl, R′ = Tol, X = Cl, 8a; E = S, R = Xyl, R′ = Me, X = Cl, 8b; E = Se, R = R′ = Me, X = BPh 4, 8c]. Finally, treatment of the zwitterionic vinyliminium complexes with I 2 results in the oxidative coupling with formation of S–S (disulfide) or Se–Se (diselenide) bond. The reactions, performed in the presence of NaBPh 4 afford the tetranuclear complexes [Fe 2{μ-η 1:η 3-C(R′) C(E)C N(Me)(R)}(μ-CO)(CO)(Cp) 2] 2[BPh 4] 2 [R = Xyl, R′ = CH 2OH, E = S, 9a; R = Xyl, R′ = Me, E = S, 9b; R = Xyl, R′ = Bu n , E = S, 9c; R = Xyl, R′ = Me, E = Se, 9d; R = Me, R′ = Bu n , E = Se, 9e]. The molecular structures of 4a, 8c and 9e have been determined by X-ray diffraction studies.