Synthesis and characterization of a persistent paramagnetic rotaxane based on alpha-cyclodextrin

J Org Chem. 2006 May 12;71(10):3773-7. doi: 10.1021/jo0601720.

Abstract

The synthesis and spectroscopic properties of a novel paramagnetic [2]rotaxane is described. This rotaxane is made from molecules having an alkyl chain flanked by 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO) groups. Complexation of sebacoyl chloride by alpha-cyclodextrin followed by reaction with a bulky aminonitroxide resulted in the trapping of the cyclodextrin, threaded by the alkyl chain, thus generating the rotaxane structure. The structure of the paramagnetic [2]rotaxane was fully characterized by ESI-MS, 1D and 2D NMR and ESR spectroscopy.