The phosphinidene-bridged complex [Fe
2Cp
2(μ-PCy)(μ-CO)(CO)
2] (
1) reacts with HC
CR (R =
p-tol, CO
2Me) to give products incorporating one or two alkyne molecules and involving further coupling with Cp or CO ligands, as shown by the formation of the comple
xes [Fe
2Cp{μ-η
5:κ
1-C
5H
4PCyCHCH(
p-tol)}(CO)
3], [Fe
2Cp
2{μ-κ
1:κ
1,η
1-CyPCHC(
p-tol)C(O)}(μ-CO)(CO)], and [Fe
2Cp
2(μ-CO)
2(CO){PCy(CHCHCO
2Me)(C
2CO
2Me)}]. In contrast, the reactions of
1 with benzyl azide or (trimethylsilyl)diazomethane initially give the simple 1:1 adducts [Fe
2Cp
2(μ-CyPN
3CH
2Ph)(μ-CO)(CO)
2] and [Fe
2Cp
2{μ-CyPN
2CH(SiMe
3)}(μ-CO)(CO)
2], respectively, although the latter rearranges to yield [Fe
2Cp
2{μ-κ
1:κ
1,η
1-CyPN(SiMe
3)NCH}(μ-CO)(CO)] under photolytic conditions.