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

Several small, lipophilic rhenium complexes form inclusion complexes with n ative 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 als o enabled the synthesis of these rhenium complexes in water, in excellent y ields, through complexation of the otherwise insoluble corresponding ligand s. The influence of the reaction time and temperature on the configuration of the reaction products has been investigated in depth for one of these co mplexes. Using a beta -CD dimer, it proved possible to specifically templat e the formation of one configuration. The strength of the complexes of the rhenium complexes in cyclodextrin dimers may allow radiolabeling of biomole cules.