A synthetic investigation of substituted cyclopentadienyl complexes of bismuth and germanium

Abstract

A series of novel cyclopentadienyl bismuth and germanium metal complexes were prepared by using the sterically bulky 2,6-bis(2,4,6- trimethylphenyl)phenylcyclopentadienyl (^TerMesCp) ligand. Mono-, bis-, and tris^TerMesCp metal complexes were prepared by reacting ^TerMesCp-K with the metal halides: GeCl₂, BiCl₃, and BiI₃. The bismuth complexes, ^TerMesCpBiI₂, (^TerMesCp)₂BiI, and (^TerMesCp)₃Bi contained trigonal pyramidal bismuth metal centers coordinated to the cyclopentadienyl ring with hapticities of η¹. The intermediate germanium complex, ^TerMesCpGeCl, contained a germanium metal center coordinated to the cyclopentadienyl ring with a hapticity of η¹. Upon further reactivity, cationic germanium species [^TerMesCpGe][GaCl₄] and [^TerMesCpGe][ B(3,5-CF₃-C₆H₃)] were synthesized with germanium metal centers coordinated to the cyclopentadienyl ring with hapicities of η⁴ and η³ respectively. In some cases, stabilizing aryl interactions with the mesityl ring of the ^TerMesCp ligand are present. Cationic germanium species, [^TerMesCp-Ge]⁺ , were synthesized by chloride abstraction from the germanium chloride using GaCl₃, or by metathesis with Na[B(3,5-CF₃-C₆H₃)].