Nucleophilicity of Ligated S₂^2- Ions. Conversion of Organic Chlorides into Organosulfur Compounds in <i>cis-</i>[(MCp*)₂(μ-CH₂)₂(μ-S₂R)]⁺ (M = Rh, Ir)

The chemically active rhodium complex cis-[(RhCp*)2(μ-CH2)2(μ-SS)], 1, activated all C−Cl bonds of polychlorinated organic compounds, namely, C6H5CCl3 and p-ClC6H4CCl3 (except ring chlorine), and formed compounds cis-[(RhCp*)2(μ-CH2)2(μ-S2C-C6H5)][BPh4], 6, and cis-[(RhCp*)2(μ-CH2)2(μ-S2C-C6H4-Cl-p)][BPh4], 7, after treatment with NaBPh4. Similarly, the iridium complex cis-[(IrCp*)2(μ-CH2)2(μ-SS)], 2, activated C−Cl bonds of p-ClC6H4-CCl3(except ring chlorine) and formed the compound cis-[(IrCp*)2(μ-CH2)2(μ-S2C-C6H4-Cl-p)][BPh4], 5. Compound 6 is analogous to cis-[(IrCp*)2(μ-CH2)2(μ-S2C−C6H5)][BPh4], 3 (obtained by reaction of 2 with C6H5CHCl2 or C6H5CCl3); however, reaction with C6H5CH2Cl formed the S-benzylated product cis-[(IrCp*)2(μ-CH2)2(μ-SS-CH2-C6H5)][BPh4], 4. Interestingly, compound 2 activated all the C−Cl bonds of CCl4 in methanol and formed the products cis-[(IrCp*)2(μ-CH2)2(μ-S2CH)][BPh4], 8, and [Ir4S4(Cp*)4(μ-CH2)4] [BPh4]2, 9. The unique reactivity of the bridged S2-dimer is that activation of C−Cl bonds occurs at S-donor atoms and not at the usual metal centers.