Oligomerization of butadiene with (η-C₅R₅)Ru^II complexes; stoichiometric and catalytic chemistry

Treatment of (η-C₅R₅)Ru(η-butadiene)X; (R H, Me; X Br, Cl) with butadiene, in the presence of silver triflate, yielded cationic complexes with 1,3,7-octatriene ligands, produced from the CC bond formation at both the terminal carbon atoms of two molecules of butadiene. In the pentamethylcyclopentadienyl system the octatriene ligand was cyclodimerized to 1,5-cyclooctadiene when treated with carbon monoxide. The ligand structure was elucidated by NMR spectroscopy. Catalytic reactions on these systems have also been studied.