Single-Crystal NMR for ¹⁷O in Alanine Enantiomers

Area of Science:

• Solid-state chemistry
• Spectroscopy
• Chirality studies

Background:

• Molecular chirality is crucial for life's origin and function.
• Solid-state Nuclear Magnetic Resonance (ssNMR) spectroscopy analyzes crystalline electronic structures.
• Investigating chirality requires detailed electronic structure analysis.

Purpose of the Study:

• To characterize the electronic structure of 17O nuclei in crystalline alanine enantiomers.
• To integrate single-crystal ssNMR, X-ray diffraction, and DFT calculations.
• To explore the power of combined methods for understanding molecular chirality.

Main Methods:

• Single-crystal ssNMR spectroscopy was employed.
• X-ray diffraction and density functional theory (DFT) calculations were utilized.
• 17O NMR tensor parameters were determined and assigned.

Main Results:

• Eight distinct 17O resonances were observed and assigned in alanine enantiomers.
• NMR tensor parameters, including antisymmetric chemical shift tensor components, were determined.
• DFT calculations supported site assignments and revealed new tensor components.

Conclusions:

• This study provides the first comprehensive characterization of 17O NMR tensors in alanine enantiomers.
• The integration of single-crystal ssNMR, X-ray diffraction, and DFT is powerful for chirality studies.
• Advanced understanding of molecular chirality in amino acids is achieved.