Experimental and theoretical insights into cationic polymerization of para-N,N-dimethylaminostyrene

Experimental and theoretical insights into palladium-mediated polymerization of para-N,N-disubstituted aminostyrene

“…However, the great increase in [M] 0 /[Pd] 0 only led to a slight increase in the polymer molecular weight from 4100 to 5300, strongly indicating that the chain transfer depended on the monomer concentration. 48,54 DMAS polymerizations at different times from 2 to 60 min were carried out to understand polymerization characteristics (Fig. 1 and Table S1†).…”

“…Overall, the DMAS polymerization using Pd2 showed reaction characteristics including no induction period, fast chain growth, and rapid chain transfer, which was very similar to DMAS polymerization using cationic initiators. 48…”

“…It has been reported that para-N , N -disubstituted aminostyrene (DSAS) monomers can be polymerized via different mechanisms including free radical, 42–44 anionic, 45–47 cationic, 48–50 and coordination–insertion mechanisms. 51–53 For polymerizations of vinyl monomers using cationic α-diimine palladium catalysts, free radical, 32–34,36–38 cationic, 39–41 and coordination–insertion 51–53 mechanisms have also been reported according to the kind of vinyl monomers.…”

“…Moreover, our previous DFT calculations have clearly demonstrated cationic polymerization of DMAS using a classic BF 3 ·OEt 2 . 48 For cationic polymerization of DMAS, chain transfer to the N , N -dimethylamine of DMAS is the major occurrence to produce an ammonium cation. The ammonium cation can easily transform into a styryl cation as the carbocation species with a small energy difference.…”

“…Notably, the polymerization mechanism can be switched by the insertion of polar vinyl monomer into the palladium center, which allows the synthesis and development of new olefin–polar monomer copolymers. 36–38,40 para-N , N -disubstituted aminostyrene (St-4-NR 2 ) is a kind of attractive monomer, which has been polymerized through different mechanisms including free radical, 42–44 anionic, 45–47 cationic, 45–50 and coordination–insertion polymerization. 51–53 Although polymerizations and oligomerizations of a few polar vinyl monomers using cationic α-diimine palladium complexes have been carried out, 39–41,54 polymerizations of para-N , N -disubstituted aminostyrene (DSAS) monomers using cationic α-diimine palladium catalysts have never been reported to date.…”