Piero Pino

Optical activity and optical rotatory dispersion in synthetic polymers

Among the large number of methods proposed for the investigation of macromolecular conformation in solution, optical activity is in principle one of the most powerful since, in general, optical activity is strongly dependent on conformational equilibria1. Its use, however, is seriously hindered by the difficulty in calculating the optical activity even of small molecules theoretically. This difficulty can be partially solved in some cases by using a semi-empirical calculation of the optical rotation2; furthermore some information concerning the relationships between optical activity and conformation in polymers can be obtained by comparing the optical activity of polymers with that of low-molecular-weight models in which intermolecular interactions between the chromophoric systems responsible for the optical rotation can often be excluded.