Radiation-induced Cis to Trans isomerization of poly( n-butylpropiolate) prepared with a [Rh(norbornadiene)Cl] 2 complex as a stereospecific catalyst

Abstract

Normal alkylpropiolate, i.e., n-butylpropiolate: HCCCOO nC 4H 9 was polymerized with [Rh(norbornadiene)Cl] 2 catalyst in methanol solvent to produce poly( n-butylpropiolate), (PBPA) polymer called polyacetylene esters in relatively high yields. The obtained polymer was characterized in detail using 1HNMR, gel permeation chromatography (GPC), diffuse reflective UV methods. Consequently, the data showed that the resulting polymers selectively have cis-transoid form. We also found that γ-ray irradiation of the cis isomer resulted in isomerization to the trans isomer even at room temperature in air to generate the extended trans sequences which can stabilize mobile unpaired electrons as π-radicals called solitons.