WELL AND BARRIER DYNAMICS AND ELECTRON-TRANSFER RATES - A MOLECULAR-DYNAMICS STUDY

被引:77
作者
SMITH, BB [1 ]
STAIB, A [1 ]
HYNES, JT [1 ]
机构
[1] UNIV COLORADO, DEPT CHEM & BIOCHEM, BOULDER, CO 80309 USA
基金
美国国家科学基金会;
关键词
D O I
10.1016/0301-0104(93)80259-C
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
Molecular dynamics simulations are carried out for model electronically adiabatic electron transfer (ET) reactions. The reactants are immersed in various model dipolar aprotic solvents, ranging from slightly overdamped to strongly overdamped. In all cases, the solvent barrier recrossings which give the solvent dynamical influence on the ET rate are determined by motion in the barrier top region, and not in the solvent wells as some current notions would have it. The MD reaction transmission coefficients are reproduced by Grote-Hynes theory to within the simulation error bars, while other analytic descriptions such as Zusman theory (in its range of applicability) and Kramers theory are less satisfactory, and fail significantly in the overdamped solvent regime. The reasons for these results as well as their implications for the interpretation of adiabatic ET rates are briefly discussed.
引用
收藏
页码:521 / 537
页数:17
相关论文
共 117 条
[91]   PICOSECOND STOKES SHIFT STUDIES OF SOLVENT FRICTION - EXPERIMENTAL MEASUREMENTS OF TIME-DEPENDENT BAND SHAPE AND INTEGRATED INTENSITY [J].
SIMON, JD ;
SU, SG .
CHEMICAL PHYSICS, 1991, 152 (1-2) :143-152
[92]   SOLVENT DIELECTRIC EFFECTS ON ISOMERIZATION DYNAMICS - INVESTIGATION OF THE PHOTOISOMERIZATION OF 4,4'-DIMETHOXYSTILBENE AND TERT-STILBENE IN NORMAL-ALKYL NITRILES [J].
SIVAKUMAR, N ;
HOBURG, EA ;
WALDECK, DH .
JOURNAL OF CHEMICAL PHYSICS, 1989, 90 (04) :2305-2316
[93]  
SMITH BB, 1992, N-HOLLAND D, P39
[94]  
SMITH BB, IN PRESS J CHEM PHYS
[95]   DIELECTRIC FRICTION AND THE TRANSITION FROM ADIABATIC TO NONADIABATIC ELECTRON-TRANSFER .1. SOLVATION DYNAMICS IN LIOUVILLE SPACE [J].
SPARPAGLIONE, M ;
MUKAMEL, S .
JOURNAL OF CHEMICAL PHYSICS, 1988, 88 (05) :3263-3280
[96]   IMPORTANCE OF MOLECULAR-SIZE ON THE DYNAMICS OF SOLVENT RELAXATION [J].
SU, SG ;
SIMON, JD .
JOURNAL OF PHYSICAL CHEMISTRY, 1989, 93 (02) :753-758
[97]   SOLVATION DYNAMICS IN ETHANOL [J].
SU, SG ;
SIMON, JD .
JOURNAL OF PHYSICAL CHEMISTRY, 1987, 91 (11) :2693-2696
[98]   NONEQUILIBRIUM AND NONADIABATIC EFFECTS ON EXCITED-STATE ELECTRON-TRANSFER REACTIONS IN SOLUTION [J].
SU, SG ;
SIMON, JD .
CHEMICAL PHYSICS LETTERS, 1989, 158 (05) :423-428
[99]   DIELECTRIC-RELAXATION AND INTRAMOLECULAR ELECTRON TRANSFERS [J].
SUMI, H ;
MARCUS, RA .
JOURNAL OF CHEMICAL PHYSICS, 1986, 84 (08) :4272-4276
[100]   INTRAMOLECULAR ELECTRON EXCHANGE IN THE 2,7-DINITRONAPHTHALENE RADICAL-ANION - ELECTRON-PARAMAGNETIC RESONANCE AND KINETIC DATA [J].
TELO, JP ;
SHOHOJI, MCBL ;
HEROLD, BJ ;
GRAMPP, G .
JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS, 1992, 88 (01) :47-51