π-Arene Complexes. 6.¹ Synthesis and Characterization of η⁶-Arene Complexes of Manganese with Sulfur-Containing Ligands

The neutral complexes (η⁶-C₆H₆)Mn(CO)₂(SPh) (R = H (1a), 3 H, 3 Me (1b), Me (1c)) have been prepared in high yields from the reaction of [(η⁶-C₆H₆)Mn(CO)₃]PF6 with Me₃NO and subsequent treatment of the reaction mixture with PhSH. Exchanging PhSH for PhSRʹ (Rʹ = Ph, Me) in this reaction led to the formation of the cationic compounds [(ƞ⁶-C₆H₃Me₃)Mn(CO)₂(S(Rʹ)Ph)]PF₆ (Rʹ = Me (5), Ph (6)). Methylation of 1b with MeOSO₂F again yielded 5. Protonation of 1a-c with HBF₄ afforded the benzenethiol complexes [(η⁶-C₆R₆)Mn(CO)₂(S(H)Ph)]BF₄ (R = H (4a), 3 H, 3 Me (4b), Me (4c)), which were characterized spectroscopically. Treatment of [(η⁶-C₆R₆)Mn(CO)₂(THF)]PF₆ with thiophenol gave the cationic dimeric compounds [((η⁶-C₆R₆)Mn(CO)₂)₂SPh]PF₆ (R = H (2a), 3 H, 3 Me (2b), Me (2c)) in quantitative yields. The structures of 1a and 2b have been determined crystallographically. The neutral complex (η⁶-C₆H₆)Mn(CO)₂SPh crystallizes in the monoclinic space group P2₁/n with a = 8.046 (3) Å, b = 14.735 (6) Å, c = 10.595 (5) Å, β = 98.11 (3)°, Z = 4, V = 1243 (1) ų, R = 0.058, and R_w = 0.051. The structure adopted a staggered conformation of the two carbonyls and the sulfur ligand relative to the π-arene carbon atoms. The cationic compound [((η⁶-C₆H₃Me₃)Mn(CO)₂)₂SPh]PF₆ crystallizes in the monoclinic space group P2₁/n with a = 8.340 (1) Å, b = 28.273 (3) Å, c = 13.350 (2) Å, β = 104.87 (1)°, Z = 4, V = 3043 (1) ų R = 0.059, and R_w = 0.047. The eclipsed conformations of the carbonyls and the sulfur ligands relative to the respective π-arene ring carbon atoms are slightly distorted.