Solution structures and exchange phenomena of the new alkene polymerization initiators (η-C5Me5)TiMe(E)(μ-Me)B(C6F5 )3 (E = C6F5, OC6F5) and [(η-C5Me5)Ti(OC6F5)2 ][BMe(C6F5)3]

Abstract

The solution structures and dynamics of the new alkene polymerization initiators (η-C 5 Me 5 )TiMe(C 6 F 5 )(µ- Me)B(C 5 F 5 ) 3 2, (η-C 5 Me 5 )TiMe(OC 6 F 5 )(µ -Me)B(C 6 F 5 ) 3 3 and [(η-C 5 Me 5 )Ti(OC 6 F 5 ) 2 ][BMe(C 5 F 5 ) 3 ] 4 are compared and contrasted with those of the known initiator (η-C 5 Me 5 )TiMe 2 (µ-Me)B(C 6 F 5 ) 3 1; compound 2 undergoes neither spontaneous ion-pair dissociation to the solvent separated [(η-C 5 Me 5 )TiMe(C 6 F 5 )] + and [BMe(C 6 F 5 ) 3 ] - nor borane dissociation to its precursors (η-C 5 Me 5 )TiMe 2 (C 6 F 5 ) and B(C 6 F 5 ) 3 ; in contrast, 3 is more labile and does undergo ion-pair dissociation, while 4 exists in solution as the separated ion species in equilibrium with its precursors, (η-C 5 Me 5 )TiMe(OC 6 F 5 ) 2 and B(C 6 F 5 ) 3 .