Rotaxanes - Novel photonic molecules

Rotaxanes are a new class of interesting macromolecules, composed from two interlocked, mobile parts. They can be processed into good optical quality thin films and exhibit interesting second and third-order nonlinear optical properties. In solution the macrocycle rotate around the thread, as it was shown previously by the electro-optic Kerr effect and NMR. The measured frequency of rotation agrees well with theoretical calculations and depends on temperature as well as on the applied external field strength. Rotaxanes can be poled, similarly as functionalized polymers. Using the third harmonic generation technique a clipping movement was demonstrated when shining in the thread absorption band.