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, [(η5-C5H4Me)4Fe4(HCCH)2]+, with N-bromosuccinimide led to stepwise bromination of two acetylene ligands to form [(η5-C5H4Me)4Fe4(HCCBr)(HCCH)]+, [(η5-C5H4Me)4Fe4(HCCBr)2]+, [(η5-C5H4Me)4Fe4(BrCCBr)(HCCBr)]+, and [(η5-C5H4Me)4Fe4(BrCCBr)2]+. The reactivity of the bromoacetylene fragment in [(η5-C5H4Me)4Fe4(HCCBr)(HCCH)]+ toward water, pyridine, and ZnMe2 was also investigated.