elucidation of more complicated systems which exhibit both Normal micelle formation has been observed for isotropic solumicellization and enantiomerism. tions of the optically active surfactants, potassium N-n-dodeca-Self-association phenomena such as micelle formation are noyl-D-and -L-alaninate, and their racemic mixture in deuterium affected by many intrinsic molecular properties such as the oxide, and in the binary solvent, ca. 11.4 wt% 1,4-dioxane in deutehydrophile-lipophile balance of the surfactant, polarity, and rium oxide. These systems display very low critical micelle concendonor-acceptor ability of the solvent, along with external trations, which are reflected in the concentration dependence of factors, e.g., temperature and pressure (1, 2). However, the the carbon-13 nuclear magnetic resonance chemical shift and prorole which optical activity plays in surfactant aggregation ton magnetic resonance peak position. Critical micelle concentrahas not been the focus of much attention, nor has the determitions are higher for the surfactant-binary solvent systems (cmc ca. 0.019 m at 30-37ЊC) compared to the similar values of the nation of critical micelle concentrations in resolved and race-D-, L-, and D,L-surfactants in deuterium oxide (cmc Å 0.011mic surfactant solutions. It has been reported that for normal 0.015 m at 30-37ЊC). The presence of a chiral center does not micelles, (i.e., hydrocarbon groups form the core and polar appreciably alter the cmc value, nor the micellization properties groups the surface of the aggregate), the critical micelle of the optically active surfactants compared to the racemate. The concentration (cmc) of the pure enantiomers are generally variation of the cmc and micellization behavior among the D-, the same, within experimental error, as the cmc value of the L-, and racemic surfactants are described in terms of enantiomerracemate. Sodium N-acylalaninates and valinates, though, ism, entropic effects, and the dielectric permittivity of the medium. are exceptions in that the pure isomers have slightly lower Information on the structure of the micelles is afforded from differcmc values (3). Also, the surface properties of some surfacence (d(micelle) 0 d(monomer)) carbon-13 NMR chemical shifts tants have been considered to be strongly stereoselective in and proton magnetic resonance peak positions as a function of that they show chiral discrimination between the properties the position of the nucleus in the surfactant ion pair.