Electron spin resonance line shape analysis of x-doxylstearic acid spin probes in dioctadecyldimethylammonium chloride vesicles

Journal Article · Thu Aug 06 04:00:00 EDT 1992 · Journal of Physical Chemistry

DOI:https://doi.org/10.1021/j100195a059· OSTI ID:468106

Bratt, P J; Kevan, L ^[1]

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1. Univ. of Houston, TX (United States)

Electron spin resonance spectra of a series of x-doxylstearic acids (x = 5, 7, 10, 12, and 16) solubilized in cationic dioctadecyldimethylammonium chloride vesicles were recorded over 298-328 K and analyzed by employing spectral line simulation. The spectra from the vesicle phase are well reproduced by using the microscopic order-macroscopic disorder model of Freed and co-workers with Brownian rotational diffusion. The partial averaging of the magnetic interactions by local anisotropic motions in the vesicles is quantified mainly by an order parameter (S) and the rotational diffusion rate perpendicular to the alkyl chain (R{sub {perpendicular}}) shows a similar, but inverse, correlation; that is R{sub {perpendicular}} increases, plateaus, and decreases with increasing x. The U-shaped conformation of the spin probe alkyl chain in liquid vesicle solutions in the same as deduced previously in frozen vesicle solutions measured by electron spin echo modulation spectroscopy. 33 refs., 8 figs., 1 tab.

• Sponsoring Organization: USDOE
• OSTI ID: 468106
• Journal Information: Journal of Physical Chemistry, Journal Name: Journal of Physical Chemistry Journal Issue: 16 Vol. 96; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
40 CHEMISTRY
66 PHYSICS
AMMONIUM CHLORIDES
ELECTRON SPECTROSCOPY
ELECTRON SPIN RESONANCE
LINE WIDTHS
ORGANIC ACIDS
SPIN ECHO