CLEAVAGE OF A BICYCLO[2.2.1]HEPTA-2,5-DIENYL LIGAND DURING TRANSFER FROM NICKEL TO RUTHENIUM - X-RAY STRUCTURE OF (MU-ETA(1),O-ETA(2)-C(CO(2)ME)=CHC(O)OME)(CO)(4)CP

The reaction between Ru-3(CO)(12) and Ni{eta(1),eta(2)-C5H5C2(CO(2)Me) (2)}Cp afforded orange Ru-2{mu-eta(1),O:eta(2)-C(CO(2)Me)=CHC(O) OMe}( CO)(4)Cp (43%) as the only isolable complex. An X-ray structure determ ination showed that a C(CO(2)Me)=CHC(O)OMe ligand bridges an Ru-Ru bon d [2.7744(9) Angstrom] via a mu-eta(1):eta(2)-vinyl interaction and by coordination of one of the ester CO groups [Ru-O 2.148(2) Angstrom]. One ruthenium atom bears three terminal CO ligands and the other ruthe nium atom has one CO ligand and an eta(5)-C5H5 group. In the reaction, transfer of Cp and the vinyl group (from the bicyclo[2.2.1]hepta-2,5- dienyl ligand originally present) from nickel to ruthenium has occurre d.