Chloranil electron acceptors polymerization

The unusual combination of a Lewis acid and an electron acceptor has also been shown to be an efficient polymerization catalyst. Thus dialkyl-aluminium halides with chloranil, 1,3,5-trinitrobenzene, and 2,4,5,7-tetranitro-fluoren-9-one succeed in polymerizing isobutene and isobutene/isoprene mixtures to very high molecular weight polymers. Chloranil was examined in most... 

Electron-transfer Initiation. Highly electron-rich monomers like A-vinylcarbazole can be polymerized readily by powerful electron acceptors such as chloranil, tetracyanoethylene, and 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ). Recently the killing of polymerizations at low conversion by addition of methanol has shown that the ion radicals initially formed combine to give a zwitterion in the case of DDQ with methyl vinyl ether (Scheme 6), although to what extent this structure is maintained throughout polymerization is not certain. 

Kang and coworkers76 have also used organic electron acceptors such as 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) and chloranil. A solvent effect was observed when polymerization was carried out using DDQ. Polymerization in acetonitrile gave the lowest conductivity, and in water it was slightly better. A similar solvent dependence was observed for chloranil oxidations. 

In contrast to the transition metal catalysts above, nickel complexes have been studied intensely for the polymerization of CHD and its derivatives. jr-Allylnickel-based complexes were employed by Dolgoplosk et al. for CHD polymerization. They used n-alkenylnickel halides, for example, K-metallyl nickel dichloride and it-allyl nickel dibromide, combined with electron acceptors such as chloranil (tetrachloro-/ -quinone) or nickel trichloroacetate. Unfortunately, the true propagating species of the above catalytic systems are not clear, but they were moderately active for CHD polymerization and the polymer obtained appeared to have a predominantly 1,4-linked structure. However, the stereoregularity of the polymer was not very high based on its Tm (270 °C). 

Polymerization of styrene with BF3 OEt2 in the presence of electron acceptors (EA) such as tetracyanoethylene (TCE) and chloranil (CA) strongly increased its rate if chlorinated solvents were used. This was not observed in the donor solvent benzene and also not in the acceptor solvent nitrobenzene [90]. This is explained by complexation of the counterion, enhancing the ion separation and therefore increasing the rate. 

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