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New phosphorous catanionic amphiphiles were easily prepared by an acid−base reaction between (α-hydroxyalkyl)-phosphinic or -phosphonic acid and cethyltrimethylammonium hydroxide. In this way, we obtained, in nearly quantitative yields, bicatenary phosphinates and bicatenary and tricatenary phosphonates. The aggregation properties of these new catanionic amphiphiles were investigated at low concentrations in water (ranging from 1 to 5 mM), focusing in particular on spontaneous formation of different aggregate morphologies (vesicles, ribbons, tubules). Light and electron microscopy was used to identify the aggregate morphology of the catanionic amphiphiles. Moreover, these catanionic amphiphiles were able to organize into ordered lyotropic mesophases in concentrated water solutions, visualized by optical polarizing microscopy. Finally, the phosphorous catanionic amphiphiles, without rigid cores, were unexpectedly found to show thermotropic liquid-crystalline behavior. The various thermotropic mesophases we...

We have studied the surfactant properties of a series of single- and double-chain (a-aminoalkyl)-phosphonocarboxylic- and (a-aminoalkyl)-phosphonic acid amphiphiles, prepared in nearly quantitative yields by one-pot selective hydrolysis of the mixture obtained by reacting P-H bond tetraoxyspirophosphorane and long-chain aldimines. Disodium salts of monocatenary derivatives are soluble in water and the cmc's were determined by tensiometry, showing surfactant properties for all compounds. Thermodynamic calculations confirmed the tensiometry results, in the sense that phosphonocarboxylates present much more electrostatic destabilizing repulsions favoring micellization less than phosphonates. The disodium salts of these phosphonic acids were able to organize into ordered lyotropic mesophases in concentrated water solutions, visualized by optical polarizing microscopy. The nature of the observed mesophases seems to be strongly dependent on the polar head structure. All compounds were studied using the Langmuir technique. The more hydrophobic derivatives formed stable monolayers versus time at the air/water interface. The areas occupied per molecule depend on the polar head structure and the number of alkyl chains. The conformations at the air/water interface were estimated by a molecular modeling study.

A new series of (α-hydroxyalkyl)phosphinic acids 1 was prepared in good yields from long-chain aldehydes (C8−C18) and 50% aqueous hypophosphorous acid under sonication. Oxidation of these phosphinic acids by dimethyl sulfoxide in the presence of catalytic amounts of iodine afforded the corresponding (α-hydroxyalkyl)phosphonic acids 2. Critical micelle concentrations (cmc) of the amphiphilic monocaternary (α-hydroxyalkyl)phosphorus acid ammonium salts 1 and 2, determined by tensiometry and 31P NMR, showed a good correlation between the two methods and indicated their high surfactant properties. The phosphonate salts 2 with two dissociable groups had much higher cmc values than those of the corresponding phosphinate analogues 1. The ammonium salts of these phosphorus acids were able to form ordered lyotropic mesophases in concentrated water solutions, visualized by optical polarization microscopy. The nature of the observed mesophases (hexagonal or lamellar) depended on the concentration, the temperature, t...