SOME INSERTION REACTIONS INTO THE TI-ME BOND OF [TI(ETA-5-C5ME5)MECL2] - CRYSTAL-STRUCTURES OF [TI(ETA-5-C5ME5)-(ETA-2-COME)CL2] AND [(TI(ETA-5-C5ME5))2(MU-CL)2(MU-ETA-4-CH2-(2,6-ME2C6H3N)C=C(NC6H3ME2-2,6)CH2)]

Treatment of (Ti(C5Me5)Cl3] with trimethylaluminium gives [Ti(C5Me5) MeCl2], which reacts readily with CO, CNC6H3Me2-2,6 and N2CPh2 to give the corresponding acyl [Ti(C5Me5)(eta2-COMe)Cl2], iminoacyl (Ti(C5Me5){eta2-MeCN(C6H3Me2-2,6)}Cl2] and hydrazonato (Ti(C5Me5){eta2-N(Me)NCPh2}Cl2] insertion products. The compound [Ti(C5Me5){eta2-COMe)Cl2] reacts with PMe3 to give [Ti(C5Me5){eta2-OC-(PMe3)Me}Cl2] and [Ti(C5Me5){OC(CNC6H3Me2-2,6)Me}Cl2] has been identified by NMR spectroscopy as the product of a similar nucleophilic attack by CNC6H3Me2-2,6. The reaction of [Ti(C5Me){eta2-MeCN(C6H3Me2-2,6)}Cl2] with nucleophilic agents like Li[N(SiMe3)2] leads to [{Ti(C5Me5)}2(mu-Cl)2{mu-eta4-CH2(2,6-Me2C5H3N)C=C(NC6H3Me2-2,6)CH2}]. The crystal structures of the latter and of [Ti(C5-Me5)(eta2-COMe)Cl2] have been established by X-ray diffraction methods; the mononuclear compound shows a pseudo-square-pyramidal geometry with a strong Ti-[eta2-C(Me)O] interaction, while the dinuclear compound contains two Ti(C5Me5) groups bridged by two chlorine atoms and by the new ligand eta4-CH2(2,6-Me2C6H3N)C=C(NC6H3Me2-2,6)CH2 reported here for the first time.