Complexation and (templated) synthesis of rhenium complexes with cyclodextrins and cyclodextrin dimers in water

Several small, lipophilic rhenium complexes form inclusion complexes with native beta -cyclodextrin (beta -CD) and P-CD dimers. Association constants larger than 10(9) m(-1) were obtained using dimers. The use of beta -CD also enabled the synthesis of these rhenium complexes in water, in excellent yields, through complexation of the otherwise insoluble corresponding ligands. The influence of the reaction time and temperature on the configuration of the reaction products has been investigated in depth for one of these complexes. Using a beta -CD dimer, it proved possible to specifically template the formation of one configuration. The strength of the complexes of the rhenium complexes in cyclodextrin dimers may allow radiolabeling of biomolecules.