Transition-metal-free controlled polymerization for poly(p-aryleneethynylene)sElectronic supplementary information (ESI) available: Experimental details and characterizations of new compounds and polymers. See DOI: 10.1039/c4sc02872d

A transition-metal-free controlled polymerization for the attainment of poly( p -aryleneethynylene)s is developed. The polymerization of 1-pentafluorophenyl-4-[(trimethylsilyl)ethynyl]benzene with a catalytic amount of fluoride anions proceeds in a chain-growth-like manner to afford polymers with controlled molecular weights and low polydispersity indexes. The mechanism involves a pentacoordinated fluorosilicate as a key intermediate. The anionic "living" nature of this process is applied to block copolymerization and also surface-terminated polymerization. A catalytic amount of fluoride anions promoted the polymerization of 1-pentafluorophenyl-4-[(trimethylsilyl)ethynyl]benzene, providing a high-molecular-weight polymer in a chain-growth-like manner.