Formation of columnar from poly(p-mehylethynylbenzene) polymerized using [Rh(norbornadiene)C1]2 as a catalyst. An X-ray and ESR study

Columnar polymers of p -methylethynylbenzene (MEB) were synthesized using [Rh(norbornadiene)Cl] 2 as a catalyst in alcohol. Polymers having a cis-transoid structure were selectively formed at high yields. The structure and properties of the polymers were analyzed by means of X-ray diffraction and ESR methods. The data showed that the pristine amorphous polymer was converted to a pseudohexagonal columnar one when it was treated with toluene at room temperature. Formation of columnar polymers was also demonstrated by the increase in the linewidth in the ESR spectra of the polymer obtained by the toluene treatment of the pristine amorphous polymer, indicating that a magnetically inhomogeneous line broadening mechanism operates among the radical spins which are heterogeneously distributed in the columnar phase.