Electronic coupling and electron transfer in hydrogen-bonded mixed-valence compounds

Area of Science:

• Physical Chemistry
• Biophysical Chemistry
• Chemical Physics

Background:

• Electron transfer mediated by hydrogen bonds is crucial in diverse chemical and biological processes.
• Hydrogen-bonded mixed-valence systems (donor-hydrogen bond-acceptor) serve as key models for studying electron transfer.
• Significant research progress has been made in understanding electron transfer across hydrogen bond interfaces.

Purpose of the Study:

• To critically assess studies on the evaluation of electronic coupling and thermal electron transfer across hydrogen bond interfaces.
• To discuss experimental examples of intervalence charge transfer.
• To highlight proton-coupled and proton-uncoupled electron transfer pathways in hydrogen-bonded mixed-valence systems.

Main Methods:

• Qualitative and quantitative evaluation of electronic coupling.
• Analysis of thermal electron transfer mechanisms.
• Experimental investigation of intervalence charge transfer.
• Distinguishing between proton-coupled and proton-uncoupled electron transfer.

Main Results:

• Electron transfer across hydrogen bonds is a significant phenomenon in various systems.
• Both proton-coupled and proton-uncoupled electron transfer pathways are relevant.
• Electronic coupling and thermal electron transfer can be quantitatively and qualitatively evaluated.
• Intervalence charge transfer provides insights into electron transfer dynamics.

Conclusions:

• The study critically reviews current understanding of electron transfer across hydrogen bonds.
• It emphasizes the importance of both proton-coupled and proton-uncoupled pathways.
• Identifies limitations and suggests future research directions in this field.