Unexpected binding mode of gemini surfactants and γ-cyclodextrin: DOSY as a tool for the study of complexation

DOSY measurements for aqueous solutions containing oxyethylene spacer gemini surfactants, in the absence and presence of γ-CD reveals the formation of complexes of 1:1 stoichiometry. This complexation is strong enough to destroy aggregates, and the NMR measurements point to an unexpected complex in which both hydrophobic chains thread one γ-CD.