Investigations on the effect of methyl group in poly(<i>o</i>-toluidine) by electrochemical and spectroscopic techniques

290-294Conducting poly(o-toluidine) polymer has been synthesized by both chemical and electrochemical polymerization methods. The presence of methyl group affects not only the electrochemical polymerization window but also brings about drastic changes in the optical and electronic properties of parent polymer polyaniline. Poly(o-toluidine) shows multiple colour transition (yellow→green→blue→violet) on switching the potential between reduced and oxidized state with a better electrochromic response time (27 ms). The hypsochromic shift of π-π*. transition and bathochromic shift of metallic polaron band transition are observed on going from polyaniline to poly(o-toluidine) which are probably due to change in torsional angle between two adjacent rings