Dehydrogenation polymerization of ortho-methoxyphenol. A theoretical study

The dehydrogenation polymerization of ortho-methoxyphenol was studied theor etically. Quantum-chemical calculations carried out for the formation of di phenyls and terphenyls showed that recombination of phenoxy radicals is the most thermodynamically favorable reaction. It was shown that an oligomer i s formed regioselectively via C-C bonds in the 1, 2, and 5 positions of an aromatic ring (OCH3 and OH groups are in the 3 and 4 positions of the ring, respectively). At the initial stages of the process, dehydropolymerization of ortho-methoxyphenol occurs via formation of 1-5 bonds. Propagation of t he C-C chain is restricted via formation of interfragmentary C-O bonds and para-quinoid structures.