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Electron flow in reaction mechanisms--revealed from first principles.
Gerald Knizia1, Johannes E M N Klein
1Institut für Theoretische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart (Germany); Present address: Department of Chemistry, Pennsylvania State University, 401A Chemistry Bldg; University Park, PA 16802 (USA). knizia@psu.edu.
Angewandte Chemie (International Ed. in English)
|March 5, 2015
Summary
Curly arrows, used to depict chemical reactions, are now shown to have a physical basis. Quantum chemistry computations directly visualize these bond rearrangements, confirming their reality and detailing reaction mechanisms.
Area of Science:
- Organic Chemistry
- Quantum Chemistry
- Computational Chemistry
Background:
- The "curly arrow" notation is a cornerstone for explaining chemical reaction mechanisms.
- The physical underpinnings and direct link to quantum chemistry for this notation have remained unclear.
Purpose of the Study:
- To investigate the physical reality of curly arrow representations in chemical reactions.
- To establish a direct connection between curly arrows and quantum chemical calculations.
Main Methods:
- Utilized ab initio quantum chemistry computations.
- Analyzed the transformations of intrinsic bond orbitals (IBOs) along the reaction coordinate.
Main Results:
- Observed bond rearrangements corresponding to curly arrows directly within computations.
- Demonstrated that curly arrows represent physically real transformations of intrinsic bond orbitals.
- Provided unprecedented detail and intuitive understanding of reaction mechanisms.
Conclusions:
- Confirms the physical basis of the widely used curly arrow notation.
- Establishes a direct bridge between intuitive reaction mechanism depiction and rigorous quantum chemistry.
- Offers a powerful new method for analyzing and visualizing chemical reactions with high detail.
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