Parity non conservation: NMR parameters in chiral molecules

Area of Science:

• Nuclear Magnetic Resonance Spectroscopy
• Quantum Chemistry
• Relativistic Effects in Chemistry

Background:

• Magnetic shielding tensors are crucial for understanding nuclear magnetic resonance (NMR) spectra.
• Parity-violating electroweak interactions offer a unique probe of fundamental physics and molecular chirality.
• Thallium-containing enantiomers present a promising system for detecting subtle NMR effects.

Purpose of the Study:

• To calculate the parity-violating electroweak interaction contribution to the magnetic shielding tensor in thallium-containing enantiomers.
• To investigate the potential for observing chemical shift differences arising from these interactions using ultra-high resolution NMR.

Main Methods:

• Application of a theoretical formula for parity-violating electroweak contributions.
• Utilizing an extended Hückel method with relativistic parameterization.
• Computational analysis of two pairs of thallium-containing enantiomers.

Main Results:

• A calculated chemical shift difference of approximately 1 mHz at 11.7 Tesla was obtained for the studied enantiomers.
• This calculated difference is comparable to, yet slightly lower than, the extreme line width achievable in ultra-high resolution NMR.

Conclusions:

• The parity-violating electroweak interaction can induce measurable chemical shift differences in thallium-containing enantiomers.
• Ultra-high resolution NMR spectroscopy may offer a pathway to experimentally detect these subtle effects, probing fundamental physics at the molecular level.