Microwave-Assisted Preparation of Poly(fluorene)s by Ni-Catalyzed Polymerization

A series of poly(fluorene)s was prepared from 9,9-dialkylated-2,7-dibromofluorenes by Ni-catalyzed polymerization (Yamamoto coupling reaction) under microwave irradiation. Compared to the oil heating bath method (24 h, Mw 12800, yield 82%), microwave irradiation of 9,9-di-n-octyl-2,7-dibromofluorene produced poly[2,7-(9,9-di-n-octylfluorene)] with a high molecular weight (Mw 24200) and yield (88%) in a short time (180 min). Hence, the microwave irradiation method effectively shortened the reaction time and increased the molecular weight of the prepared poly(fluorene)s.