mu-benzyl and mu-chloro dinuclear cationic titanium compounds

The reaction of [Ti(eta (5)-C5H4SiMe2-kappaO)(CH2Ph)(2)](2) with the Lewis acid B(C6F5)(3) in toluene at room temperature affords the new dinuclear mo nocationic species [{Ti(eta (5)-C5H4SiMe2-kappaO)}(2)(CH2Ph)(3)]+[PhCH2B-(C 6F5)(3)](-) (1). This compound is thermally unstable and decomposes in arom atic solvents to give the paramagnetic mixed-valence species [{Ti(eta (5)-C 5H4SiMe2-kappaO)}(CH2-Ph)](2)+Q(-)(Q(-) = [PhCH2B(C6F5)(3)]- (2), [B(C6F5)( 4)](-) (3)). In chlorinated solvents I affords the mu -chloro complexes [{T i(eta (5)-C5H4SiMe2-kappaO)(CH2Ph)}(2)(mu -Cl)](+)Q(-) (Q(-) = [PhCH2B(C6F5 )(3)](-) (4), [B(C6F5)(4)](-) (5)). Different isomers of 1 are observed, de pending on the temperature, as deduced by variable-temperature NMR spectros copic studies.