A molecular density functional theory approach to electron transfer reactions

Area of Science:

• Physical Chemistry
• Computational Chemistry
• Theoretical Chemistry

Background:

• Electron transfer (ET) reactions are fundamental in chemistry and biology.
• Standard methods like molecular dynamics simulations are computationally intensive.
• Existing theories often simplify solvent effects, limiting accuracy.

Purpose of the Study:

• To develop a computationally efficient theoretical method for studying electron transfer reactions.
• To accurately model the molecular nature of solvents in ET processes.
• To investigate the influence of interfaces on electron transfer.

Main Methods:

• Reformulating molecular electron transfer theory within a molecular density functional theory (MDFT) framework.
• Computing ET observables, including the vertical energy gap and Marcus free energy curves.
• Applying MDFT to model Cl → Cl+ and Cl → Cl- reactions in water and at a solid-solvent interface.

Main Results:

• MDFT provides a computationally efficient alternative to molecular dynamics for ET.
• The method successfully calculates thermodynamic quantities like reaction and reorganization free energies.
• The Cl → Cl- reaction in water deviates from predictions of standard Marcus theory.
• The study analyzes the impact of a solid-solvent interface on reorganization free energy.

Conclusions:

• Molecular density functional theory is a viable and efficient approach for studying electron transfer reactions.
• The findings highlight limitations of standard Marcus theory for certain ET reactions.
• The method's efficiency allows for the investigation of complex systems, including interfaces.