The synthesis of novel, unsymmetrically substituted, chiral naphthalene and perylene diimides: Photophysical, electrochemical, chiroptical and intramolecular charge transfer properties

A novel naphthalene monoimide and two unsymmetric chiral diimides (naphthalene and perylene) were synthesized; for comparison purposes, the perylene monoimide with the same substituent in the naphthalene monoimide was prepared. The naphthalene monoimide exhibited intramolecular charge transfer complexation in polar solvents. Excimer-like emissions were obtained in non-polar, polar protic and aprotic solvents in the cases of both the naphthalene monoimide and diimide. The specific optical rotation values of unsymmetrical chiral naphthalene and perylene diimides were −221.6 and −24, respectively at 20 °C. The Chiral naphthalene diimide showed prominent, negative Cotton effects centred at 362 and 382 nm in CH3CN.