ELECTRON-SPIN RESONANCE LINE-WIDTH METHOD FOR MEASURING DIFFUSION - CRITIQUE

被引:56
作者
BERNER, B [1 ]
KIVELSON, D [1 ]
机构
[1] UNIV CALIF LOS ANGELES,DEPT CHEM,LOS ANGELES,CA 90024
关键词
D O I
10.1021/j100474a012
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
The concentration (C) dependent part of the ESR line width (ΔH) of a paramagnetic solute in a diamagnetic solvent arises from intermolecular interactions between paramagnetic molecules, and these interactions are strongly modulated by the translational motions of these molecules. Thus (d ΔH/dC) depends upon the diffusion constant (D), and measurements of (dΔH/dC) can be used to determine D. Although this method of measuring D may not be the most favored one for bulk media, it could be one of the few methods applicable to the study of diffusion within bilayers. We have evaluated this procedure for measuring D by studying (dΔH/dC) in a number of bulk solvents over a very wide range of (T/η) where T is the temperature and η is the solvent viscosity. At low viscosity, the spin-exchange interactions dominate, and dΔH/dC is linear in D or in (T/η). At moderate viscosities dΔH/dC varies little with (T/η) because the dipolar interaction which varies as D-1 competes with the spin-exchange interaction. In fact, (dΔH/dC) remains relatively constant over quite a wide range of (T/η), but at very low T/η the (dΔH/dC) values evidence an upsweep with decreasing (T/η). The low (T/η) results are not yet understood, but it is clear that (dΔH/dC) gives useful diffusion data at low viscosities (high T/η) only. © 1979 American Chemical Society.
引用
收藏
页码:1406 / 1412
页数:7
相关论文
共 35 条
[1]  
ABRAGAM A, 1961, PRINCIPLES NUCLEAR M, P302
[2]  
Anisimov O. A., 1971, Theoretical and Experimental Chemistry, V7, P556, DOI 10.1007/BF00527165
[3]   ESR studies of DTBN in a model lipid water system [J].
Bales, B. L. ;
Baur, M. E. .
CHEMICAL PHYSICS LETTERS, 1970, 7 (03) :341-344
[4]   ELECTRON-PARAMAGNETIC RESONANCE STUDIES OF HEISENBERG SPIN EXCHANGE IN A NEMATIC LIQUID-CRYSTAL [J].
BALES, BL ;
SWENSON, JA ;
SCHWARTZ, RN .
MOLECULAR CRYSTALS AND LIQUID CRYSTALS, 1974, 28 (1-2) :143-153
[5]  
BALES BL, COMMUNICATION
[6]   PARAMAGNETICALLY ENHANCED RELAXATION OF NUCLEAR SPINS - MEASUREMENT OF DIFFUSION [J].
BERNER, B ;
KIVELSON, D .
JOURNAL OF PHYSICAL CHEMISTRY, 1979, 83 (11) :1401-1405
[7]  
BERNER B, 1978, THESIS U CALIFORNIA
[8]  
Bevington P., 1969, DATA REDUCTION ERROR
[9]  
DEGENNES PG, 1974, PHYSICS LIQUID CRYST
[10]  
DEVAUX P, 1973, J MAG RESON, V9, P479