2007 年 65 巻 2 号 p. 139-150
Aromatic chain imides possessing chromophores connected by iminodicarbonyl linkers were synthesized as novel aromatic foldamers. In these molecules chromophores face each other and form the helical folding structures both in solution and in solid state. Their folding structures were investigated by single crystal X-ray analysis and 1H NMR spectroscopy. A circular dichroism (CD) spectral study on the chiral aromatic chain imides with bulky N-substituents showed that their helically chiral conformation based on folding remained for a reasonably long time without racemization in solution. As the number of folded chromophores increased, their absorption and fluorescence spectra were red-shifted, and induced CD signals were increased. This remarkable change is based on the intramolecular interaction between folded chromophores. As an application of these aromatic chain imides, a chiral photochromic system was investigated by utilizing the intramolecular photo [4+4] cycloaddition and thermal cycloreversion of anthracene and naphthalene chromophores connected by iminodicarbonyl linkers.