Synthesis and reactions of Ru(CH2)Cl(NO)(PPh3)2, a stable terminal methylene complex and the crystal structure of Ru(CH2PPh3)(η2-C2F4)Cl(NO)(PPh3)

Abstract

Treatment of RuCl(NO)(PPh₃)₂ with CH₂N₂ in diethyl ether at room temperature affords Ru(CH₂)Cl(N)(PPh₃)₂1. Complex 1 undergoes a reaction with each of the reagents HCl, [Aul₂]^–, HgCl(C₆H₄Me-p), HgCl₂ and SO₂ forming respectively RuMeCl₂(NO)(PPh₃)₂2, [graphic omitted]ul)Cl(NO)(PPh₃)₂3, Ru[CH₂Hg(C₆H₄Me-p)]Cl₂(NO)(PPh₃)₂4a, Ru(CH₂HgCl)Cl₂(NO)(PPh₃)₂4b and [graphic omitted]]Cl(NO)(PPh₃)₂5. Treatment of 1 with PhC₂Ph at room temperature affords the unstable complex Ru(CH₂PPh₃)(η²-PhC₂Ph)Cl(NO)(PPh₃)6. Reaction of 1 with ethylene under the same conditions gives, as a final product, Ru(η²-C₂H₄)Cl(NO)(PPh₃)₂11. An NMR investigation of the production of 11 confirmed the presence of the intermediate Ru(CH₂PPh₃)(η²-C₂H₄)Cl(NO)(PPh₃)10, and the formation of propene as 11 was generated, suggesting a possible metallacyclopropane intermediate. In contrast, treatment of 1 with C₂F₄ yields Ru(CH₂PPh₃)(η²-C₂F₄)Cl(NO)(PPh₃)7, exclusively, the structure of which was confirmed by single-crystal X-ray diffraction. The metal geometry is that of a distorted trigonal bipyramid, with the triphenylphosphine and the ylide carbon occupying the apical sites. The osmium analogue of 7, Os(CH₂PPh₃)(η²-C₂F₄)Cl(NO)(PPh₃)8, is obtained from a similar reaction.