Magnetically oriented lyotropic luquid crystalline phases

Abstract

treatment with P-glucuronidase the urine was adjusted to pH 4.7 and again extracted with ether. The major metabolites in this ether extract were 3-chlorophen01,~ 4-chlorophenol, and 4-chlorocatechol. Two minor metabolites were 2-chlorophenolg and an 0-methyl ether of 4-chlorocatechol.g Strong acidification of the remaining urine and further ether extraction led to the isolation of 4-chlorophenylmercapturic acid (S-4chlorophenyl-N-acetylcysteine). The deuterium retentions observed in all the metabolites isolated are presented in Table I. The same three monophenols benzenediol has been isolated from the urine of rabbits t o which 4-deuteriochl~robenzene~ had been administered. Eleven New Zealand white female rabbits (-1 kg) were injected intraperitoneally with 2.0 g each of 4deuteriochlorobenzene applied in a 1 : 1 emulsion with water containing 0.25% each of oleic acid and triethanolamine. Urine was collected for 48 hr and adjusted t o pH 8. The ether extract provided about 4 mg (0.014 %) of 6-deuterio-5,6-dihydroxy-3-chloro-1,3cyclohexadiene (VI) as a crystalline solid (mp 129-130", lit.4 129-130" for the hydrogen compound) containing exactly 1.0 deuterium atom. The stability of this glycol t o acid4s6 and triacetyl~smate~ suggests the trans configuration VI (only one antipode is pictured arbitrarily).About 1 mg of the glycol VI was dehydrated with 1.0 N HC1 at 100" for 10 min. The phenolic products were methylated with dimethyl sulfate in oxygen-free 1 .O N NaOH at 80" for 2-3 min, conditions under which no appreciable exchange occurs. The resulting chloroanisoles were examined by combined glpc-mass spectrometry with Carbowax columns operating at 115-130". The mixture consisted of 99% 4-and 1 % 3chloroanisole. The 4-chloroanisole contained 0.23, and the 3-chloroanisole approximately 0.84 deuterium atom per molecule. When the dehydration was conducted at room temperature in 1.0 N HC1 for 4 days, the isolated p-chloroanisole contained 0.19 deuterium atom per molecule. The retention of 19-23% deuterium in the 4-chlorophenol (XVI) by acid-catalyzed dehydration of the glycol VI compares with 54% retention in vivo where the phenol XVI is probably formed directly (I -I11 ---t IV -+ V) rather than via the glycol I1 or VI.The relatively slow aromatization of the trans-glycol VI suggests a cationic transition state XI11 rather than a concerted (cis) elimination. This migration, concomitant with dehydration, is reminiscent of pinacol rearrangements in which the migratory group is hydrogen.7 Migrations of hydrogen are known to occur enzymatically in the dehydration of aliphatic pinacols where they are then subject to stringent steric and mechanistic requirements.s These results allow two conclusions: (i) retention of deuterium in the dehydration of the glycol VI involving cationic intermediates, such as XIII, is significant; (ii) the nonenzymatic formation of a 3-chlorophenol (isolated as 3-chloroanisole), from the glycol VI with 16% of the deuterium lost, suggested initially that hydrogen underwent migration by pathway IX ...

Rheological and phase behaviour of amphiphilic lipids

“…They were discovered by Lawson and Flautt (1967) and have been detected in ternary or quaternary systems at higher surfactant concentration than diluted lamellar mesophases (Hoffmann, 1994), in binary systems containing fluorocarbon (Hoffmann, 1984) or polymer (Lühmann et al, 1985) or nonionic surfactants (Lühmann and Finkelman, 1986).…”

Temperature-concentration behaviour of the order parameter in the nematic phases of a lyotropic liquid crystal

“…Mixtures in aqueous solutions, of amphiphilic molecules having a hydrophilic head and a hydrophobic tail may torm anisotropic micellar aggregates [1] which under particular conditions, may exhibit an orientational long-range ordering characteristic of the nematic phases. According to symmetry arguments, three types of lyotropic nematic phases are possible, and indeed, have been observed : two are uniaxial [2] and another one is biaxial [3].…”

Liquid crystal/glass interface effects on the orientation of lyotropic liquid crystals in magnetic fields

“…The lyotropic liquid crystals, based on water and amphiphiles, in certain systems have a significant property that they spontaneously orient in magnetic fields (1). Both positive (type I) and negative (type 11) diamagnetic anisotropies occur for these lyotropic uniaxial fluids (2,3) and a considerable amount of chemical work has been done to extend the number of known systems which have this useful property (2-7).…”