A Solvent-Free Method for Isotopically or Radioactively Labeling Cyclodextrins and Cyclodextrin-Containing Polymers

A method for installing a distinguishable label onto cyclodextrins or cyclodextrin-containing polymers is reported. Cyclodextrins (CD) and cyclodextrin-containing polymers are exposed to labeled (^2H or ^(14)C) ethylene oxide (EO) vapor and the alcohol groups on the CD ring open the EO to give ether-linked labeled methylenes and a terminal alcohol. This method provides for the incorporation of an easily tracked and quantified label without the use of solvents or purification steps. The method can be generalized for use with materials that contain nucleophiles other than alcohols, e.g., amines.