Reductive decomposition of cationic half-titanocene(IV) complexes, precursors of the active species in syndiospecific styrene polymerization

Mixtures of Cp*TiR(3) (with Cp* = C-5(CH3)(5) and R = CH3, (CH3)-C-13) and equimolar amounts of B(C6F5)(3) or C(C6H5)(3)B(C6F5)(4), active in the syndiospecific polymerization of styrene, have been investigated by means of ESR spectroscopy. At room temperature the formation of Cp*TiR(+) complexes has been observed. Rapid insertion of styrene occurs in Ti-R bonds of these cationic Ti(lll) complexes, strongly suggesting their role in the stereospecific polyinsertion