Migratory insertion reaction in alkenyl ruthenium(II) complexes containing a trifluoroacetate ligand. X-ray structure of the Ru(η²- O<inf>2</inf>CCF<inf>3</inf>)(η¹-O=CCH=CH ^tBu)(CO)(PPh<inf>3</inf>)<inf>2</inf> complex

Reaction of compound Ru(O2CCF3)(CH=CHtBu)(CO)(PPh3) 2 with CO gives the η1-alkeneacyl complex Ru(O2CCF3)(O=CCH=CHtBu)(CO)(PPh 3)2, which is in equilibrium with the dicarbonyl Ru(O2CCF3)(CH=CHtBu)(CO)2(PPh 3)2 derivative in CH2Cl2 solution. The η1-acyl form involves an η1-coordination of the O2CCF3 ligand, whereas the dicarbonyl form contains the carboxylate ligand η2-coordinated to the metal. The same mixture of carbonylated compounds can be obtained from the reaction of Ru(CH=CHtBu)Cl(CO)2(PPh3)2 with Na[O2CCF3] in a CH2Cl2/MeOH solution. These reactions reveal the significance of ancillary bidentate ligands for the η-nature of the acyl-metal bond. The molecular structure of the complex Ru(O2CCF3)(O=CCH=CHtBu)(CO)(PPh 3)2 was established by X-ray diffraction study of a monocrystal obtained from a CH2Cl2/MeOH solution of the mixture of carbonylated compounds.