A novel computational method for comparing vibrational circular dichroism spectra
Jian Shen1, Chengyue Zhu, Stephan Reiling
1Chemical and Analytical Science, Sanofi Aventis Inc., 1041 Route 202-206, Bridgewater, NJ 08807, USA. jian.shen@sanofi-aventis.com
Summary
A new method, SimIR/VCD, aids in comparing experimental and calculated vibrational circular dichroism (VCD) spectra. This approach simplifies molecular chirality assignment by reducing manual effort and potential errors in spectral matching.
Area of Science:
- Spectroscopy
- Computational Chemistry
- Chiroptical Methods
Background:
- Vibrational Circular Dichroism (VCD) spectroscopy is a powerful tool for determining molecular chirality.
- Accurate comparison between experimental and calculated VCD spectra is crucial for reliable chirality assignment.
- Manual spectral matching can be time-consuming and prone to human error.
Purpose of the Study:
- To develop a novel, objective method for comparing experimental and calculated VCD spectra.
- To enhance the accuracy and efficiency of molecular chirality assignment using VCD data.
- To provide a quantitative measure of confidence in VCD-based chiral assignments.
Main Methods:
- Development of the SimIR/VCD method based on novel spectral similarity metrics.
- Implementation of computationally optimized frequency scaling and shifting for spectral alignment.
- Validation using (1S)-(-)-alpha-pinene as a model compound.
- Comparison of VCD spectra calculated using various Density Functional Theory (DFT) methods and basis sets.
Main Results:
- The SimIR/VCD method demonstrates a strong correlation between calculated spectral similarity and experimental VCD spectra matching quality.
- The method shows sensitivity in identifying spectral variations, facilitating accurate chirality assignment.
- Significant reduction in the need for time-consuming manual band-fitting procedures.
- (1S)-(-)-alpha-pinene spectra correctly matched using the developed method.
Conclusions:
- The SimIR/VCD method offers an efficient and unbiased approach for matching experimental and calculated VCD spectra.
- This technique is expected to reduce human error in spectral analysis and chiral assignment.
- SimIR/VCD provides a valuable confidence measure for VCD spectroscopy in determining molecular chirality.
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