Hp. Xia et al., SYNTHESIS AND CHARACTERIZATION OF BIMETALLIC RUTHENIUM COMPLEXES BRIDGED WITH C5H AND RELATED LIGANDS, Organometallics, 16(13), 1997, pp. 2940-2947
Treatment of [(eta(5)-C5R5)Ru(L)(2)]BF4 (R = Me, (L)(2) = dppe; R = H,
(L)(2) = (PPh3)(2)) with 0.45 equiv of HC=CCH(OH)C=CH led to the form
ation of the C5H2-bridged compounds L)(2)Ru=C=C=CHCH=C=Ru(L)(2)(eta(5)
-C5R5)](BF4)(2). The C5H2-bridged compounds reacted with alumina to gi
ve the C5H-bridged compounds -C5R5)(L)(2)Ru=C=C=CHC=CRu(L)(2)(eta(5)-C
5R5)]BF4. The structure of the C5H-bridged complex [Cp(PPh3)(2)Ru=C=C=
CHC=CRu(PPh3)(2)Cp]BPh4 has been confirmed by X-ray diffraction and sh
ows the bridging C5H ligand to be symmetric with a delocalized st-syst
em. Reaction of )-C5R5)(L)(2)Ru=C=C=CHC=CRu(L)(2)(eta(5)-C5R5)]BF4 wit
h acetone in the presence of KOH or KOBut produced R5)(L)(2)RuC=CCH(CH
2COMe)C=CRu(L)(2)(eta(5)-C5R5).