Abstract/Details

## NEW ASPECTS OF THE THEORY OF ELECTRON TRANSFER REACTION DYNAMICS

ONUCHIC, JOSE NELSON.
California Institute of Technology ProQuest Dissertations Publishing,  1987. 8719689.

### Abstract (summary)

This thesis deals with some new aspects of the electron transfer theory. Chapter I gives an introduction to the electron transfer problem.

In Chapter II the following dynamical problems are addressed. For the case of one overdamped reaction coordinate, the problem of adiabaticity and non-adiabaticity is considered in details. For an underdamped reaction coordinate, a preliminary discussion is given. All this information is developed using a density matrix formalism and path integral techniques. One of the advantages of using this formalism is that, by analyzing the spectral density, we can connect our microscopic Hamiltonian with macroscopic quantities. It also gives us a natural way of including friction in the problem. We also determine when the Hopfield semiclassical or the Jortner "quantum" models are good approximations to the "complete" Hamiltonian. In the limit that the reaction coordinates are "classical," we discuss how we can obtain the Fokker-Planck equation associated with the Hamiltonian.

By adding more than one reaction coordinate to the problem (normally two), several other problems are studied. The separation of "fast" quantum modes from "slow" semiclassical modes, where the fast modes basically renormalize the electronic matrix element and the driving force of the electron transfer reaction, is discussed.

In Chapter III we discuss calculations of electronic matrix elements, which are essential for the calculation of non-adiabatic rates. It starts with a discussion of why, through bond rather than through space, electron transfer is the important mechanism in model compounds. Also, it explains why tight-binding Huckel calculations are reasonable for evaluating these matrix elements, and why, through space and through bond, matrix element decays with distance have a different functional dependence on energy. Bridge effects due to different hydrocarbon linkers are also calculated.

This chapter concludes with a model for the calculation of matrix elements in proteins.

In Chapter IV we discuss some experimental results obtained for electron transfer in the porphyrin-phenyl-(bicyclo (2.2.2) octane)$\sb {n}$-quinone molecule, and we propose some new experiments that should help to clarify our interpretation. It concludes with some preliminary discussions of how we can include entropy in the finite mode formalism described in Chapter II. (Abstract shortened with permission of author.)

### Indexing (details)

Subject
Chemistry;
Biophysics
Classification
0494: Chemistry
0786: Biophysics
Identifier / keyword
Pure sciences; Biological sciences
Title
NEW ASPECTS OF THE THEORY OF ELECTRON TRANSFER REACTION DYNAMICS
Author
ONUCHIC, JOSE NELSON
Number of pages
303
Degree date
1987
School code
0037
Source
DAI-B 48/08, Dissertation Abstracts International
Place of publication
Ann Arbor
Country of publication
United States
ISBN
979-8-206-17047-4
University/institution
California Institute of Technology
University location
United States -- California
Degree
Ph.D.
Source type
Dissertation or Thesis
Language
English
Document type
Dissertation/Thesis
Dissertation/thesis number
8719689
ProQuest document ID
303548770