Inclusion of organic pollutants in cyclodextrins and derivatives

Both (-)-geosmin and (+)-2-methyl-isoborneol are the main compounds responsible for the unpleasand smells found in the vicinity of water-processing plant. Attempts to eliminate them using oxidation, filtration and/or biologic degradation processes are only partly efficient. The use of cage molecules could provide an alternative solution. In this respect, cyclodextrins and derivatives have demonstrated their role as candidates as hosts for these highly hydrophobic compounds. In this paper, we evidence the complexation of above mentionned pollutants by cyclodextrins using high-resolution proton Nuclear Magnetic Resonance spectroscopy. The latter method is also used to afford a three-dimensional structure of inclusion complexes in solution and to show that cyclodextrins can as well discriminate between the optical isomers of synthetic geosmin and methyl-isoborneol. Finally, a solution to the problem of waste waters is proposed.