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Importance of Polarizable Embedding for Computing Optical Rotation: The Case of Camphor in Ethanol
Michele Nottoli1, Edoardo Vanich2, Lorenzo Cupellini2
1Institute of Applied Analysis and Numerical Simulation, Universität Stuttgart, Pfaffenwaldring 57, D-70569, Stuttgart, Germany.
The Journal of Physical Chemistry Letters
|July 30, 2024
Summary
Computational chemists can now accurately model optical rotation in solvents. A new polarizable embedding method using quantum mechanics/molecular mechanics (QM/MM) with the AMOEBA force field closely matches experimental results.
Area of Science:
- Computational Chemistry
- Physical Chemistry
- Spectroscopy
Background:
- Optical rotation is sensitive to solvent effects, posing challenges for computational modeling.
- Accurate prediction of molecular optical rotation requires accounting for solvent polarization.
Purpose of the Study:
- To develop and apply a polarizable embedding QM/MM method for calculating optical rotation.
- To investigate the impact of solvent polarization on the optical rotation of camphor in ethanol.
Main Methods:
- Density functional theory (DFT) combined with the AMOEBA polarizable force field.
- Quantum mechanics/molecular mechanics (QM/MM) with continuum, electrostatic embedding, and polarizable embedding models.
- Classical molecular dynamics simulations.
Main Results:
- The QM/AMOEBA polarizable embedding model achieved quantitative agreement with experimental optical rotation values.
- Polarizable embedding provided a significantly different qualitative picture compared to electrostatic embedding.
- Electrostatic embedding results were statistically uncorrelated with polarizable description results.
Conclusions:
- Polarizable embedding QM/MM is crucial for accurate optical rotation calculations in solution.
- Accounting for environmental polarization is essential for reliable predictions of solvent effects on molecular properties.
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