Stepwise bromination of two acetylene molecules on a butterfly-type tetrairon core and reactivity of the resulting bromoacetylene fragment toward nucleophiles

Treatment of the acetylene-coordinated tetrairon cluster, (eta5-C5H4Me)4Fe4(HCCH)2]+, with N-bromosuccinimide led to stepwise bromination of two acetylene ligands to form (eta5-C5H4Me)4Fe4(HCCBr)(HCCH)]+, (eta5-C5H4Me)4Fe4(HCCBr)2]+, (eta5-C5H4Me)4Fe4(BrCCBr)(HCCBr)]+, and (eta5-C5H4Me)4Fe4(BrCCBr)2]+. The reactivity of the bromoacetylene fragment in (eta5-C5H4Me)4Fe4(HCCBr)(HCCH)]+ toward water, pyridine, and ZnMe2 was also investigated.