Photophysical properties of thin films and solid phase of switchable supermolecular anthracene-based rotaxanes

Polycrystalline powders and thin films of a novel rotaxane, methyl-exopyrid ine-anthracene rotaxane (EPAR-Me), and of the related thread and stoppers 1 0-[3,5-di (ter butyl)phenoxy]decyl-2-({2-[(9-anthrylcarbonyl) amino] acetyl }amino) acetate (ANTPEP), have been characterised by photoluminescence, abs orption and photoluminescence excitation spectroscopy. A rather unusual, i. e. unstructured and largely red-shifted, photoluminescence spectral behavio ur of the rotaxane has been found. Preliminary time resolved measurements i ndicate a fast energy transfer from the anthracene unit to different specie s the nature of which is still not assigned. (C) 2001 Elsevier Science B.V. All rights reserved.