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Relationship between Rotational Barriers and Charge Shifts.
1Department of Chemistry , Yale University , New Haven , Connecticut 06520 , United States.
The Journal of Organic Chemistry
|July 30, 2019
Summary
Quantifying conjugation and hyperconjugation stereoelectronic effects is possible using computational methods. These analyses reveal linear relationships between rotational barriers and charge shifts in various organic molecules.
Area of Science:
- Organic Chemistry
- Computational Chemistry
Background:
- Conjugation and hyperconjugation are fundamental stereoelectronic effects in chemistry.
- These effects are typically understood through qualitative descriptions.
Purpose of the Study:
- To develop a quantitative approach for analyzing conjugation and hyperconjugation.
- To investigate the energetic consequences of these stereoelectronic interactions.
Main Methods:
- Utilizing the natural bond orbital (NBO) method for energetic estimations.
- Employing charge shift analysis to study electronic redistribution.
- Comparing charge distributions between ground and transition states.
Main Results:
- Established quantitative links between stereoelectronic effects and molecular properties.
- Identified linear relationships between rotational barriers and charge shifts.
- Observed competition between sigma- and pi-charge transfer influencing molecular behavior.
Conclusions:
- Conjugation and hyperconjugation can be quantitatively assessed.
- Charge transfer dynamics are crucial in determining rotational barriers.
- Computational methods offer valuable insights into stereoelectronic effects.
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