Dynamics of Meso-Chiral Interconversion in a Butterfly-Shape Overcrowded Alkene Rotor Tunable by Solvent Properties.
Kalathil K Kartha1, Atsuro Takai1, Zdeněk Futera2
1Molecular Design and Function Group, National Institute for Materials Science (NIMS), 1-2-1 Sengen, Tsukuba, Ibaraki, 305-0047, Japan.
Angewandte Chemie (International Ed. in English)
|April 27, 2021
Summary
This study reveals how molecular rotors change shape, interconverting between chiral and meso forms. Solvent choice significantly influences this molecular motion and conformation, impacting its dynamics.
Area of Science:
- Chemistry
- Molecular Dynamics
- Supramolecular Chemistry
Background:
- Understanding molecular rotational motion is crucial but challenging.
- Overcrowded butterfly-shape alkene (FDF) molecules exhibit complex rotational dynamics.
Purpose of the Study:
- To investigate the reversible diastereomeric interconversion of a molecular rotor (FDF).
- To examine the influence of temperature and solvents on FDF's dual rotatory motion and conformational preferences.
Main Methods:
- Detailed examination of FDF's diastereomeric interconversion.
- Analysis of free energy profiles for rotor motion.
- Correlation of conformational ratios with solvent properties.
Main Results:
- FDF exhibits interconversion between chiral trans-FDF and meso cis-FDF diastereomers.
- The free energy profile for rotation is bimodal with distinct transition states.
- Aromatic solvents favor the meso cis-conformation, while non-aromatic solvents favor the chiral trans-conformation due to solvophobic effects.
Conclusions:
- Solvent interactions, particularly solvophobic effects, dictate the conformational preference of FDF.
- Molecular rotor dynamics are tunable via solvent selection, offering control over diastereomeric states.
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