Synthesis and reactivity of fac-[Fe(CO)3(SR)3]− (R=C7H4SN, C4H3S, C4H2O-o-CH3) and heterotrimetallic Fe(II)–Ni(II)–Fe(II)–thiolate complex

The reaction of 2 equiv. of diorganyl disulfides, (bis(2-benzothiazolyl) disulfide, di(2-thienyl) disulfide, and bis(2-methyl-3-furyl) disulfide), with 1 equiv. of [HFe(CO)4]− affords the stable, tridentate fac-[Fe(CO)3(SR)3]− (R=C7H4SN (1); C4H3S (2); C4H2O-o-CH3 (3)) via the formation of intermediate [RSFe(CO)4]−, respectively. In contrast, oxidative addition of 2-aminophenyl disulfide to [Fe(CO)4(SC6H4-o-NH2)]−, obtained from reaction of [HFe(CO)4]− and 2-aminophenyl disulfide, and concomitant displacement of [SC6H4-o-NH2]− leads to the neutral monomeric compound cis-[Fe(CO)2(SC6H4-o-NH2)2] (6). Obviously, the reactivity and stability of the iron–thiolate derivatives may be tailored by pendant ligand selection, and the reaction pathway is tailored according to the bond strength inherent in the organodisulfides and to the nucleophilicity of thiolate atoms in [RSFe(CO)4]− complexes. In particular, compounds fac-[Fe(CO)3(SR)3]− serve as chelating metalloligand and intermetal thiolate ligand-transfer reagent to synthesize the linear heterotrinuclear [(CO)3Fe(μ-SR)3Ni(μ-SR)3Fe(CO)3] (4) (R=C4H2O-o-CH3) and the neutral [Fe(CO)2(SC4H3S)2(bipy)] (5) (bipy=bipyridine).