PI-ELECTRON DELOCALIZATION IN CONFORMATIONALLY DISTORTED OLIGOPYRROLES AND POLYPYRROLE

Effective conjugation coordinate (ECC) theory has previously been used to interpret the Raman spectra of oligopyrroles and polypyrrole, providing information on conjugation and delocalization. However, the materials used in real applications have long alkaline side chains (to aid solubility), which leads to conformational distortion. ECG theory is now applied to ''protected'' molecules, showing that a quantitative estimate of the extent of localization in conformationally distorted polypyrrole can be obtained from their Raman spectra.