The [(η⁵-C₅Me₅)(2,2‘-bipyridine)Ru]^- Anion and Its Use in the Synthesis of Alkyl, Gallyl, and Stannyl Complexes of Ruthenium

Reduction of Cp*(bipy)RuCl (Cp* = η5-C5Me5, bipy = 2,2'-bipyridine) with an excess of KC8 in THF generated the dark purple-red anionic ruthenium complex K[Cp*Ru(bipy)] (2a). The analogous lithium salt Li[Cp*Ru(bipy)] (2b) was generated in situ by reaction of Cp*(bipy)RuCl with 2 equiv of lithium naphthalenide. Complex 2a was structurally characterized as the crown adduct [K(dibenzo-18-crown-6)][Cp*Ru(bipy)] (2a·dibenzo-18-crown-6). Dark purple crystals of this complex were obtained from a THF/pentane solution, and its structure was determined by X-ray diffraction. The solid state structure features two ion pairs of 2a in its asymmetric unit. In a reaction with MeI, compound 2a was converted to the methyl complex Cp*(bipy)RuMe (3). Complex 2a reacted with Me3SnCl to produce the ruthenium stannyl complex Cp*(bipy)RuSnMe3 (4). Reaction of 2a with TripGaCl2(THF) in THF gave the ruthenium gallyl derivative Cp*(bipy)Ru(GaClTrip) (5).