Cyclopolymerization of dipropargyl derivatives by Cp2MoCl2-EtAlCl2 catalyst system

Abstract

A Cp[2MoCl2-EtAlCl2 catalyst system was used for the cyclopolymerization of various dipropargyl derivatives having different functionalities. These catalyst systems were found to be very effective for the polymerization of some dipropargyl monomers to give a relatively high yield of polymer. The polymerization behaviors were strongly dependent on the functionalitics of dipropargyl monomers. The polymerization of such dipropargyl monomers as 1,6-heptadiyne, diphenyldipropargyl methane. diethyldipropargyl malonate, etc. proceeded well to give a quantitative yield, whereas this catalyst system was found to be less effective for the polymerization of dipropargyl monomers having perfluoroalkyl groups and quaternary ammonium salts. The polymer structure of the resulting polymers was characterized by various instrumental methods such as NMR, IR, and UV-visible spectroscopies to have a conjugated polyene backbone system with cyclic recurring units. The portion of 5- and 6-membered rings of the present conjugated cyclopolymer were also discussed.