Degrees of order of solubilized alkanes, alcohols, carboxylates, and carboxylic acids in oriented lyomesophases

Abstract

. Can. J. Chem. 55, 2404 (1977).The degree of order of solubilized molecules and ions in oriented lyomesophases has been determined at specifically deuterated C-D bond axes from the quadrupole splitting of the deuterium magnetic resonance. Mixtures at low concentration of specifically deuterated alkanes, alcohols, carboxylic acids, and carboxylates of different chain length have been observed in host cationic and anionic lyomesophases. The degree of order of a given C-D position in alcohols increases strongly with chain length up to a length comparable with the host detergent. A broad series of carboxylic acids and carboxylate ions from C2 to CI6 have been deuterated in the a position. The a-C-D bond axis in the solubilisate increases in order with chain length, the anion having lower order than the parent acid. An accurately linear increase in the degree of order of the a position is observed for intermediate chain lengths. At chain lengths approximately equal to the host chain lengths the a position reaches a limiting value in the degree of order and further segments do not influence the order. At short chain lengths the degree of order is less than that predicted from extrapolation of order in the linear region. This has been interpreted in terms of distribution into the aqueous compartment by the solubilisates of short chain length. Acetic acid and the acetate, propionate, butanoate, and pentanoate ions spend an appreciable amount of time in the aqueous region. An estimate has been made of these distributions based on reasonable assumptions. On a dttermine le degrt d'ordre des moltcules et des ions solubilists dans des lyomtsophases orienttes; ces ttudes ont tte effectutes par rapport a des axes de liaisons C-D deuttrts d'une f a~o n spkifique a partir des couplages quadrupolaires de la rtsonance magnetique du deuterium. On a observt, dans des lyomtsophases cationique et anionique agissant comme hbtes, des melanges contenant de faibles concentrations d'alkanes, d'alcools, d'acides carboxyliques et de carboxylates de longueurs de chaine difftrentes et deuttres d'une f a~o n sptcifique. Le degrt d'ordre pour une position C-D donnte dans les alcools augmente d'une f a~o n tres prononcte avec la longueur de la chaine jusqu'a une longueur comparable a celle du dttergent agissant comme h6te. On a deuterk en position a une grande strie d'acides carboxyliques et d'ions carboxylates allant de C2 a CI6. L'ordre de l'axe de liaison a-C-D des moltcules solubilistes augnlente avec la longueur de la chaine; l'anion a un ordre plus bas que celui de l'acide qui lui a donne naissance. On observe une augmentation lineaire prtcise dans le degrt d'ordre dans la position a pour des longueurs intermtdiaires de la chaine.A des longueurs de chaine approximativement tgales a celles des longueurs de chaine de la moltcule hbte, la position a atteint une valeur limite dans le degrt d'ordre et des segments suppltmentaires n'influencent pas l'ordre. Aux courtes longueurs de chaine, le degre d'ordre est plus faible que celui prtdit a par...

Location and Average Alignment of Alkylpyridinium Ions in Cationic Nematic Lyomesophases

“…Carboxylic acids in an anionic system similarly show a linearity with hydrocarbon chain length. 18 The observations of alkyl carboxylates in an anionic decyl sulfate mesophase18 reveals an intermediate behavior between alkyl alcohols and the pyridinium ions of this study.…”

Micellar super-structure in magnetically aligned lyotropic liquid crystals studied by light scattering

“…In the last few years, Reeves and co-workers have been studying magnetically aligned lyotropic liquid crystals by means of nmr spectroscopy (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11). The structure of most of these mesophases is not known and a tentative classification based on magnetic properties was proposed by Reeves et al (6).…”

Order profiles of host decyl sulfate and decylammonium chains and guest carboxylic acids and carboxylates in aligned type II DM lyomesophases

“…The increase in degree of order of the a-CD2 of the acids and carboxylate amphiphiles per CH2 segment added was found to be linear over a region of chain lengths less than the half-bilayer distance of the host mesophase. 6 At chain lengths for the guests which approach the host half-bilayer thickness, there is no further increase in degree of order at the a position. At short chain lengths of the carboxylates, the distribution into the interstitial water is appreciable and leads to deviations from the linear dependence.…”

“…At short chain lengths of the carboxylates, the distribution into the interstitial water is appreciable and leads to deviations from the linear dependence. 6 The a-CD2 segments of the carboxylate amphiphiles in the host micelle bilayer of sodium decyl sulfate (SDS), decanol, water, and sodium sulfate are lower in degree of order than those of the carboxylic acids, except at very long chain lengths of 12 or more carbons. In this previous study6 there was no 0022-3654/80/2084-0662 $01.00/0 © 1980 American Chemical Society The size of the disks in the upper part of the diagram may have a more or less broad distribution.…”