Sugar-based cationic surfactants: Synthesis and aggregation of methyl 2-acylamido-6-trimethylammonio-2,6-dideoxy-D-glucopyranoside chlorides

The synthesis of the sugar-based cationic surfactants methyl 2-acylamido-6-trimethylammonio-2,6-dideoxy-D-glucopyranoside chlorides is reported here. Aggregation of these surfactants (predominantly a anomers) in water was studied at 25 degreesC by conductivity measurements. Increasing the chain length of the amido group R decreased the critical micelle concentration (CMC) and the degree of counter-ion dissociation. The dependence of the Gibbs' free energy of micellization and CMC on the length of R is similar to that observed for other ionic surfactants. The free energy of transfer of the head group, i.e., cationic amino sugar moiety, from water to the micelle is more negative than that of other ionic surfactants, including sodium methyl 2-acylamido-2-deoxy-6-O-sulfo-D-glucopyranosides, probably due to a combination of a micellar "medium" effect and intermolecular H-bonding in the micellar pseudophase.