Conformational peculiarities of alcohols incorporated in lyotropic and thermotropic liquid crystals.
Conformational characteristics of 1-butanol incorporated not only in hexagonal and lamellar aggregates formed by a lyotropic liquid crystal composed of sodium octanoate, 1-butanol, and water but also in a thermotropic liquid crystal, 4'-methoxybenzylidene-4-n-butylaniline (MBBA), have been investigated from 2H NMR quadrupolar splittings of the perdeuterated and partially deuterated compounds. In the lyotropic phases, 1-butanol shows strong trans preferences and renders itself extended, and octanoate decreases the trans fraction toward the methyl terminal to fill the inner space of the aggregate on behalf of 1-butanol. In MBBA, 1-butanol prefers globular conformations. This tendency was also indicated from the phase behaviors of 1-butanol/MBBA and 1-decanol/MBBA systems. In the nematic field, two successive C-C bonds of 1-butanol mostly adopt g+/-g+/- conformations, which are formed in the vicinity of the headgroup of 1-decanol in the lamella of the sodium octanoate/1-decanol/water system. A large degree ofconformational freedom near the hydroxyl group of alcohols, being shown by ab initio molecular orbital calculations at the Gaussian-2 level, permits them to change conformation for each environment.
Sasanuma
Yuji
Y
Department of Materials Technology, Faculty of Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan. sasanuma@faculty.chiba-u.jp
Nishimura
Futoshi
F
Wakabayashi
Hiroaki
H
Suzuki
Akihiro
A
D020001:1-Butanol / Q000737:chemistry; D000438:Alcohols / Q000737:chemistry*; D000814:Aniline Compounds / Q000737:chemistry*; D001597:Benzylidene Compounds / Q000737:chemistry*; D002210:Caprylates / Q000737:chemistry; D003460:Crystallization; D003903:Deuterium / Q000737:chemistry; D005233:Fatty Alcohols / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008823:Micelles; D018625:Microscopy, Atomic Force; D008968:Molecular Conformation; D044367:Phase Transition; D013501:Surface-Active Agents / Q000737:chemistry; D013816:Thermodynamics; D014867:Water / Q000737:chemistry
D000438:Alcohols; D000814:Aniline Compounds; D001597:Benzylidene Compounds; D002210:Caprylates; D005233:Fatty Alcohols; D008823:Micelles; D013501:Surface-Active Agents; D014867:Water; C029383:n-decyl alcohol; D020001:1-Butanol; D003903:Deuterium; C021056:N-(4-methoxybenzylidene)-4-butylaniline; C031492:octanoic acid; C023650:aniline