A cationic allenylideneruthenium(II) complex with two bulky hemilabile phosphine ligands

Abstract

The allenylidene complex [RuCl(CCCPh₂)(κ²-P,O-Cy₂PCH₂CH₂OCH₃)₂]PF₆ (2) has been prepared from [RuCl₂(κ²-P,O-Cy₂PCH₂CH₂OCH₃)₂] (1) and HCCC(OH)Ph₂ in the presence of AgPF₆. Protonation of 2 with HBF₄ in diethyl ether leads to the formation of the dicationic ruthenium carbyne [RuCl(CCHCPh₂)(κ²-P,O-Cy₂PCH₂CH₂OCH₃)(κ-P-Cy₂PCH₂CH₂OCH₃)]²⁺, which is catalytically less active in olefin metathesis than related species with RuHCl(CCH₃) as a molecular unit. The molecular structure of 2 has been determined by X-ray crystallography.