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, prov iding information on conjugation and delocalization. However, the mate rials 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 es timate of the extent of localization in conformationally distorted pol ypyrrole can be obtained from their Raman spectra.