Migratory insertion reaction in alkenyl ruthenium(II) complexes containinga trifluoroacetate ligand. X-ray structure of the Ru(eta(2)-O2CCF3) (eta(1)-O = CCH = CH(t)BU) (CO) (PPh3)(2) complex

Reaction of compound Ru(O2CCF3)(CH=(CHBu)-Bu-t)(CO)(PPh3)(2) with CO gives the eta(1)-alkeneacyl complex Ru(O2CCF3)(O=CCH=(CHBu)-Bu-t)(CO) (PPh3)(2), which is in equilibrium with the dicarbonyl Ru(O2CCF3)(CH=(CHBu)-Bu-t) (CO) (2)(PPh3)(2) derivative in CH2Cl2 solution. The eta(1)-acyl form involves a n eta(1)-coordination of the O2CCF3 ligand, whereas the dicarbonyl form con tains the carboxylate ligand eta(2)-coordinated to the metal. The same mixt ure of carbonylated compounds can be obtained from the reaction of Rut CH=( CHBu)-Bu-t)Cl(CO)(2)(PPh3)(2) with Na[O2CCF3] in a CH2Cl2/MeOH solution. Th ese reactions reveal the significance of ancillary bidentate ligands for th e eta-nature of the acyl-metal bond. The molecular structure of the complex Ru(O2CCF3)(O=CCH=(CHBu)-Bu-t)(CO)( PPh3)(2) was established by X-ray diffr action study of a monocrystal obtained from a CH2Cl2/MeOH solution of the m ixture of carbonylated compounds. (C) 1999 Elsevier Science S.A. All rights reserved.