Related Experiment Videos
Chiroptical properties of 2,2'-bioxirane
N Daugey1, N De Rycke2, T Brotin2
1Institut des Sciences Moléculaires, Bordeaux University, Talence, France.
Chirality
|January 10, 2018
Summary
Chiroptical properties of 2,2'-bioxirane enantiomers were studied using polarimetry, VCD, and ROA. DFT calculations accurately predicted optical rotation and spectral data, revealing solvent-dependent conformational changes.
Area of Science:
- Chiroptical spectroscopy
- Computational chemistry
- Organic synthesis
Background:
- 2,2'-bioxirane exists as enantiomers.
- Understanding molecular conformation and optical properties is crucial in stereochemistry.
Purpose of the Study:
- To synthesize and investigate the chiroptical properties of 2,2 '-bioxirane enantiomers.
- To elucidate the influence of solvents on molecular conformation and optical activity.
- To validate computational methods for predicting these properties.
Main Methods:
- Synthesis of 2,2 '-bioxirane enantiomers.
- Chiroptical measurements: polarimetry, vibrational circular dichroism (VCD), and Raman optical activity (ROA).
- Density functional theory (DFT) calculations (B3LYP/aug-cc-pVTZ) with polarizable continuum model (PCM).
Main Results:
- DFT revealed three conformers (G+, G-, cis) with specific Gibbs populations.
- Solvent dielectric constants influenced the G+ and G- conformer ratios.
- Time-dependent DFT/PCM accurately predicted specific optical rotation, except for benzene.
- VCD and ROA spectra were well-reproduced by DFT/PCM for Boltzmann-averaged conformers.
Conclusions:
- Computational methods, particularly DFT/PCM, are effective for predicting chiroptical properties of 2,2 '-bioxirane.
- Solvent effects play a significant role in modulating the conformational landscape and optical behavior.
- The study provides a robust framework for analyzing chiral molecules in solution.