Synthesis and reactivity of η5-germacyclopentadienyl complexes of iron

Reaction of 2 equiv of the previously reported germolyl anion Li[C4Me4GeSi(SiMe3)(3)] with FeCl2(THT)(1.5) (THT = tetrahydrothiophene) at low temperature gave the new bis-eta(5)-germolyl complex [eta(5)-C4Me4GeSi(SiMe3)(3)](2)Fe (1), which was characterized by X-ray crystallography. Reaction of 1 with I-2 resulted in loss of the germolyl ligand as C4Me4Ge(I) [Si(SiMe3)(3)], while the reaction with MeLi produced the ferrocenophane ansa-(Me3Si)(2)Si(eta(5)-GeC4Me4)(2)Fe (4). X-ray crystallographic analysis of this compound revealed that the Ge atoms are displaced significantly out of the C-4 plane. Attempts to induce the ring-opening polymerization of 4 were unsuccessful.