A COMBINED NMR AND ELECTRON-SPIN-RESONANCE INVESTIGATION OF THE (C-5(CH3)(5))TI(CH2C6H5)(3)/B(C6F5)(3) CATALYTIC-SYSTEM ACTIVE IN THE SYNDIOSPECIFIC STYRENE POLYMERIZATION

The reaction of(C-5(CH3)(5))Ti(CH2C6H5)(3) with B(C6F5)(3) in chlorobenzene at 25 degrees C produces a mixture of [(C-5(CH3)(5))Ti(CH2C6H5)(2)](+) [B(CH2C6H5)(C6F5)(3)](-) (1) and Ti(III) complexes which have been characterized by NMR and electron spin resonance (ESR) spectroscopy, respectively Spectroscopic data combined with polymerisation activity measurements suggest that a Ti(III) complex is the active species in the styrene syndiospecific polymerisation.