Electron spin resonance and proton matrix electron nuclear double resonance studies of N,N,N[prime],N[prime]-tetramethylbenzidine photoionization in sodium and lithium dodecyl sulfate micelles: Structural effects of crown ethers

Journal Article · Thu Jan 07 04:00:00 EST 1993 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100103a044· OSTI ID:6566455

McManus, H J.D.; Kang, Young Soo; Kevan, L ^[1]

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

The study of model membrane systems enjoys increasing attention within the area of solar energy research. An electron nuclear double resonance and electron spin resonance study of photogenerated N,N,N[prime],N[prime]-tetramethylbenzidine (TMB) cation in frozen suspensions of lithium (LDS) and sodium (SDS) dodecyl sulfate micelles containing various concentrations of cyclic polyethers was undertaken. The relative location of the TMB cation within the organic aggregate was determined from the proton matrix ENDOR line width at 142 K. A broader line width was observed in LDS compared to SDS micelles, which is due to the fact that the larger lithium cation opens the micellar interface resulting in increased hydration and deeper solubilization of TMB. The proton matrix ENDOR line width decreased upon addition of crown ethers. This decrease may be explained by displacement of the TMB toward the interface as a result of the decrease in ionic strength caused by the complexation of the countercations. The photoyield shows a slight increase with addition of crown ethers. This increase is most likely caused by the increase in the effective anionic charge of the micelle effected by the complexation of the sodium or lithium ions by the crown ethers. This increase in the anionic charge mitigates the rate of thermal back electron transfer resulting in an increased photoyield. 54 refs., 6 figs., 2 tabs.

• OSTI ID: 6566455
• Journal Information: Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 97:1; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140505 -- Solar Energy Conversion-- Photochemical
Photobiological
& Thermochemical Conversion-- (1980-)
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500* -- Photochemistry
ALKALI METALS
AMINES
AROMATICS
BENZIDINE
CATIONS
CHARGED PARTICLES
CROWN ETHERS
DISPERSIONS
ELECTRON SPIN RESONANCE
ELECTRON TRANSFER
ELEMENTS
ENDOR
ETHERS
HYDRATION
IONIZATION
IONS
LITHIUM
MAGNETIC RESONANCE
METALS
MICELLAR SYSTEMS
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
PHOTOIONIZATION
RESONANCE
SODIUM
SOLVATION
SURFACTANTS
SUSPENSIONS