The synthesis, structure, and reactivity of cationic η4-cyclobutadiene–ruthenium complexes; formation of the trisethylene(η-cyclopentadienyl)ruthenium cation
Abstract
Reaction of [Ru(CO)2(η-C5H5)]2 with AgBF4 and PhC2Ph affords [Ru(CO)(η4-C4Ph4)(η-C5H5)][BF4], which on u.v. irradiation in MeCN gives [Ru(NCMe)(η4-C4Ph4)(η-C5H5)][BF4] identified by X-ray crystallography; similar irradiation of the carbonyl cation in the presence of alkynes or ethylene gives the sterically hindered arene cations [Ru(η6-arene)(η-C5H5)][BF4] and [Ru(η2-C2H4)3(η-C5H5)][BF4].