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A diabatic state model for double proton transfer in hydrogen bonded complexes
1School of Mathematics and Physics, University of Queensland, Brisbane, 4072 Queensland, Australia.
The Journal of Chemical Physics
|September 15, 2014
Summary
This study models double proton transfer in hydrogen bonded complexes, revealing how donor-acceptor separation and proton affinity ratios dictate potential energy surfaces and transfer mechanisms, from synchronous to sequential.
Area of Science:
- Physical Chemistry
- Chemical Physics
- Computational Chemistry
Background:
- Double proton transfer is crucial in hydrogen-bonded systems.
- Understanding transfer mechanisms requires detailed potential energy surface analysis.
Purpose of the Study:
- To develop a simple model for double proton transfer.
- To investigate the influence of key parameters on potential energy surfaces and transfer mechanisms.
Main Methods:
- Utilized four diabatic states to construct a simplified model.
- Analyzed the impact of proton donor-acceptor separation (R) and proton affinity ratio (D1/D2).
Main Results:
- The model predicts four distinct ground state potential energy surfaces based on R and D1/D2.
- Identified conditions for zero, one, two, or four saddle points, corresponding to different tautomer stabilities.
- Observed a transition from synchronous concerted to asynchronous concerted to sequential transfer as R decreases.
Conclusions:
- The model provides insights into the complex dynamics of double proton transfer.
- Parameter variations significantly alter the potential energy landscape and reaction pathways.
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