Pentaphenylgermole (1-germa-1,2,3,4,5,-pentaphenylcyclopenta-2,4-diene) reacts with diiron enneacarbonyl in refluxing diethyl ether to produce an orange, crystalline complex. This complex was established by single crystal X-ray diffraction to be the result of a novel hydroferration of the GeC σ-bond of the germacyclopentadiene moiety. The structure is of the type, RR′Ge[Fe(CO) 4] 2, in which R is a phenyl and R′ is the butadienyl fragment. The RR′Ge group bridges the FeFe bond of the Fe 2(CO) 8 fragment. The coordination about each iron atom is distorted octahedral with one Fe, the Ge, and 4 CO's making up the coordination sphere. Three pairs of carbonyls are eclipsed and the structure shows severe distortions to relieve the non-bonded repulsions between these eclipsed carbonyl groups. The relevant crystal parameters are: a 11.466(3), b 11.228(4), c 16.178(5) », α 91.41(2), β 108.99(2), γ 101.34(2)°, V 1922(1) » 3, ρ = 1.46, Z = 2, space group = P 1 . The final R-values, vased 3234 reflections with I > 3σ( I) are R = 0.079 and R w = 0.095 with all non-hydrogen atoms included with isotropic temperature factors except for the two iron and germanium atoms which are anisotropic. Some molecular parameters are (distances in pm): GeFe 1, 240.8(2); GeFe 2, 243.0(2); Fe 1Fe 2, 278.5(3); FeCO, 174 ± 2; GeC, 198 ± 2, CO, 117 ± 2; Fe 1-GeFe 2, 70.30(8); GeFe 1Fe 2, 55.23(6); GeFe 2Fe 1, 54.47(6); and CGeC, 105.5(5).