Syntheses, reactivity, and pi-donating ligand metathesis reaction of five-coordinate sixteen-electron manganese(I) complexes: Crystal structures of [Mn(CO)(3)(-TeC6H4-o-NH-)](-), [(Mn(CO)(3))(2)(mu-SC6H4-o-S-S-C6H4-o-mu-S-)], [(CO)(3)Mn(mu-SC6H4-o-NH2-)](2), and [(CO)(3)Mn(mu-SC8N2H4-o-S-)](2)(2-)

[[abstract]]The preparation of the varieties of five-coordinate sixteen-electron manganese(I) complexes [Mn(CO)(3)(-EC6H4-o-E ' (-))](-) (E = Te, Se, S, O; E ' = NH, S, O) by (a) oxidative addition of 2-aminophenyl dichalcogenides to anionic manganese(0)-carbonyl, (b) pi -donating ligand metathesis reaction of complex [Mn(CO)(3)(-TeC6H4-o-NH-)](-), and (c) reduction /deprotonation of the neutral dimetallic [(Mn(CO)(3))(2)(mu -SC6H4-o-S-S-C6H4-o-mu -S-)]/[(Co)(3)Mn(mu -sC(6)H(4)-o-NH2-)](2) proved successful approaches in this direction. The IR v(CO) data of the coordinatively and electronically unsaturated [Mn(CO)(3)(-EC6H4-o-E '-)](-) (E = Te, Se, S, O; E ' = NH, S, O) complexes suggest the relative order of pi -donating ability of the series of bidentate ligands being [TeC6H4-o-NH](2-) > [SeC6H4-o-NH](2-) > [SC6H4-o-NH](2-) > [SC6H4-o-S](2-) > [SC6H4-o-O](2-) > [OC6H4-o-O](2-). Proton NMR spectra of the [Mn(CO)(3)(-EC6H4-o-NH-)](-) (E = Te, Se, S) derivatives show the low-field shift of the amide proton (H-1 NMR (C4D8O): delta 9.66 (br) ppm (E = Te), 9.32 (br) ppm (E = Se), 8.98 (br) ppm (E = S)). The formation of the dimetallic [(CO)(3)Mn(mu -SC8N2H4-o-S-)](2)(2-) can be interpreted as coordinative association of two units of unstable mononuclear [(CO)(3)Mn(-SC8N2H4-o-S-)](-) and reflects the pi -donating ability of the bidentate ligand is responsible for the formation of pentacoordinate, sixteen-electron manganese(I) carbonyl complexes. The neutral bimetallic manganese(I)-bismercaptophenyl disulfide complex [(Mn(CO)(3))(2)(mu -SC6H4-o-S-S-C6H4-o-mu -S)] with internal S-S bond length of 2.222(1) Angstrom and the five-coordinate sixteen-electron complex [Mn(CO)(3)(-SC6H4-o-S-)](-) are chemically interconvertible. In a similar fashion, treatment of complex [Mn(CO)(3)(-SC6H4-o-NH-)](-) with HBF4 yielded neutral dinuclear complex [(CO)(3)Mn(mu -SC6H4-o-NH2-)](2) and showed that the amine deprotonation is reversible. Investigations of st-donating ligand metathesis reactions of complex [Mn(CO)(3)(-TeC6H4-o-NH-)](-) revealed that the stable intermediate, not the pi -donating ability of bidentate ligands, is responsible for the final protonation/oxidation product. This argument is demonstrated by reaction of [Mn(CO)(3)(-TeC6H4-o-NH-)](-) with 1,2-benzenedithiol, hydroxythiophenol, and catechol, respectively lending to the formation of [Mn(CO)(3)(-EC6H4-o-E '-)](-) (E = S, O; E ' = S, O), although any pi -donor containing the amido group is a more effective donor than any other st-donor lacking an amido group.[[fileno]]2010313010006[[department]]化學