SELF-ASSEMBLY, SPECTROSCOPIC, AND ELECTROCHEMICAL PROPERTIES OF [N]ROTAXANES

Synthetic approaches to self-assembling [n]rotaxanes incorporating pi- eleclron deficient bipyridinium-based dumbbell-shaped components and p i-electron rich hydroquinone-based macrocycles have been developed. In particular, the so-called slippage methodology relies upon the size c omplementarity of preformed macrocyclic and dumbbell-shaped components . The spontaneous self-assembly of these complementary components into a rotaxane in solution can be achieved under the influence of an appr opriate amount of thermal energy. The absorption spectra, luminescence properties, and electrochemical behavior of the rotaxanes and their d umbbell-shaped components have been investigated and discussed on the basis of the behavior of their chromophoric and electroactive units. C harge-transfer and energy-transfer processes between specific chromoph oric subunits and unusual correlations between the redox patterns of t he various compounds have been evidenced and interpreted.