Synthesis and crystal structure of the double cluster [Cp3Fe4(CO)4(C5H4)]2(p-C6H4)

[Cp4Fe4(CO)4] (1) reacts with p-BrC6H4Li and MeOH in sequence to afford the functionalized cluster [Cp3Fe4(CO)4(C5H4-p-C6H4Br)] (2), while the reaction of 2 with n-BuLi and MeOH produces [Cp2Fe4(CO)4(C5H4Bu)(C5H4-p-C6H4Br)] (3). The double cluster [Cp3Fe4(CO)4(C5H4)]2(p-C6H4) (4) has been prepared by treatment of [Cp4Fe4(CO)4] with p-C6H4Li2 and MeOH in sequence. The electrochemistry of 2 and 4, as well as the crystal structure of 4 have been investigated.