Three-centers models for electron transfer through a bridge. 1. Potential energy surfaces

Area of Science:

• Theoretical Chemistry
• Physical Chemistry
• Chemical Physics

Background:

• Electron transfer through bridges is crucial in chemical and biological systems.
• Existing models, like Bersuker-Borshch-Chibotaru and Lambert-Nöll-Schelter, provide frameworks for understanding this process.
• Potential energy surfaces are key to describing the dynamics of electron transfer.

Purpose of the Study:

• To present a novel three-center model for electron transfer through molecular bridges.
• To offer a more physically grounded interpretation of model parameters and coordinates.
• To elucidate the role of potential energy surface topology in electron transfer phenomena.

Main Methods:

• Development of a new three-center model inspired by the Bersuker-Borshch-Chibotaru model.
• Detailed analysis of diabatic and adiabatic potential energy surfaces.
• Application of the model to explain experimental observations in mixed valence systems.

Main Results:

• The model describes diabatic surfaces as three revolution paraboloids forming an isosceles triangle.
• Introduction of an energy shift parameter (Delta) and a depth parameter (d) for characterizing the system.
• The 'd' parameter successfully explains the differing behavior of anthracene- and dimethoxybenzodithiophene-bridged mixed valence systems.

Conclusions:

• The proposed model offers a refined understanding of electron transfer dynamics through bridges.
• The 'd' parameter is identified as a critical factor influencing the behavior of mixed valence systems.
• The model provides a valuable tool for predicting and analyzing electron transfer processes.