Synthesis of an Alkyne-Bridged Decamethylhafnocene Dimer and Related Alkyne-Substituted Monomers

Reaction of Hf*Cl 2 ( 1; Hf* = decamethylhafnocene), with excess sodium acetylide at room temperature results in the synthesis of Hf*(CCH) 2 ( 2) . The identical reaction in refluxing THF results in the dimeric product [(μ2-C2)(Hf*CCH)2] (4). Subsequent reaction of 2 with lithium diisopropylamide (LDA) in the presence of trimethyltin chloride resulted in the trimetallic Hf*(CCSnMe3)2 (3).