Preparation of beta-cyclodextrin polyrotaxane: photodimerization of pseudo-polyrotaxane with 2-anthryl and triphenylmethyl groups at the ends of poly(propylene glycol).

[structure: see text] A polyrotaxane containing beta-cyclodextrins has been prepared by photoreactions of a precursor complex between beta-cyclodextrin with poly(propylene glycol) having a triphenylmethyl group at one end and a 2-anthryl group at the other end.