First Room Temperature Chiral Anionic Liquid Forming Micelles and Reverse Micelles.

We report the first chiral surface active anionic liquid, T12M, derived from biodegradable tartaric acid, and its unusual properties. T12M features unprecedented combination of characteristics not found in other ionic liquids (ILs): (a) T12M is the first surface active ionic liquid that is fully chiral, by virtue of the presence of chirality in both anionic headgroup and the counterion; (b) T12M remains as room temperature IL for 3 days and then transforms to a semisolid with melting point at ∼55 °C. The d-spacings in solid T12M, and T12M lyophilized from its aqueous solution, are 13.89 and 14.54 Å, respectively. (c) Tartaric acid is unconventional and unprecedented starting material for the synthesis of ILs. (d) T12M dissolves in both hydrogen bonding (water) and non-hydrogen bonding (chloroform) solvents and forms anionic chiral micellar aggregates (CMAs) and reverse-CMAs, at very low concentrations 0.32 mM and ∼10 mM, respectively. (e) CMAs of T12M adopt structures ranging from spherical to lamellar in shape in water in the 10-200 mM range; however, the zeta potential remained constant at ∼ -13 mV. The alkyl chains, are interdigited in the CMAs of T12M in water to form lamellar structures and are extended outward to form reverse micelles in CHCl3.