Synthesis and Reactivity of η⁵-Germacyclopentadienyl\nComplexes of Iron

Abstract

Reaction of 2 equiv of the previously reported germolyl anion Li[C₄Me₄GeSi(SiMe₃)₃] with\nFeCl₂(THT)_1.5 (THT = tetrahydrothiophene) at low temperature gave the new bis-η⁵-germolyl\ncomplex [η⁵-C₄Me₄GeSi(SiMe₃)₃]₂Fe (<b>1</b>), which was characterized by X-ray crystallography.\nReaction of <b>1</b> with I₂ resulted in loss of the germolyl ligand as C₄Me₄Ge(I)[Si(SiMe₃)₃], while\nthe reaction with MeLi produced the ferrocenophane <i>ansa</i>-(Me₃Si)₂Si(η⁵-GeC₄Me₄)₂Fe (<b>4</b>).\nX-ray crystallographic analysis of this compound revealed that the Ge atoms are displaced\nsignificantly out of the C₄ plane. Attempts to induce the ring-opening polymerization of <b>4</b>\nwere unsuccessful.