Unpaired-electron localization and delocalization in macromolecules with a system of conjugated C=C bonds

The radical polymerization of acetylene monomers has been studied in a wide temperature range (77–340 K) using EPR spectroscopy, calorimetry, chromatography, and gravimetry It has been found that the growing macroradical is active, and its unpaired electron is localized at a terminal fragment of the molecule. However, it lost its activity even at small chain lengths (less than ten monomer units) because of delocalization of the unpaired electron along the system of conjugated double bonds.