A NOVEL LIVING COORDINATION POLYMERIZATION OF PHENYLALLENE DERIVATIVES BY PI-ALLYLNICKEL CATALYST

Coordination polymerizations of para-substituted phenylallenes (2a-2e) were carried out by using [(pi-allyl)NiOCOCF3](2) (1) as an initiator . The polymerizations were found to proceed through a living mechanism to yield polymers exclusively composed of 2,3-polymerized units in hi gh yields, where the resulting polymers have predictable molecular wei ghts and narrow molecular weight distributions, From kinetic studies, the polymerization rate was found to increase with the electron-donati ng character of the para substituent in 2. The coordination polymeriza tions of alpha-methylphenylallene (2f) and gamma-methylphenylallene (2 g) were also carried out to produce soluble polymers. In these cases, the methyl substituent on the allene moiety (especially at the gamma-p osition) was found to reduce the polymerizability. A plausible polymer ization mechanism was also discussed based on the results obtained in the study.