Studies on addition of arynyl Grignard reagents to (μ-dithio)bis(tricarbonyliron): —Synthesis,structures and formation mechanism of “open” and “closed” iron-sulfur cluster complexes

Arynylmagnesium bromides cleave the S? S bond of μ-S₂Fe₂(CO)₆ to give equilibrium mixtures of “open” intermediates (μ-ArC≡CS) (μ-BrMgS)Fe₂(CO)₆ and “closed” intermediates μ-S(Ar)C=C(MgBr)S]Fe₂(CO)₆. The mixtures were treated with CpFe(CO)₂I or some of organic halides to yield corresponding “open” Fe-S complexes, whereas with CF₃CO₂H, gaseous HBr or CH₃HgCl to afford the “closed” ones. The “closed” products were also observed with those alkyl halides which eliminate HX easily. So, this kind of alkyl halides possibly functions as substrates through elimination of HX in reaction courses