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Reprint of: Localization of Cl-35 Nuclei in Biological Solids using Rotational-Echo Double-Resonance Experiments
D Iuga1, P Rossi2, J Herzfeld2
1Department of Physics, University of Warwick, Coventry CV4 7AL, UK.
Solid State Nuclear Magnetic Resonance
|August 8, 2017
Summary
This study demonstrates solid-state Nuclear Magnetic Resonance (NMR) can measure short distances between carbon-13 and chlorine-35 nuclei. The rotational-echo double-resonance technique quantifies quadrupolar interaction effects for precise localization.
Area of Science:
- Solid-state Nuclear Magnetic Resonance (NMR) spectroscopy.
- Quantum chemistry and molecular interactions.
- Materials science and structural analysis.
Background:
- Chloride ions are crucial in various chemical and biological systems.
- Accurate determination of internuclear distances is vital for understanding molecular structures and interactions.
- Solid-state NMR offers a powerful, non-destructive method for probing atomic nuclei within solid materials.
Purpose of the Study:
- To investigate the feasibility of localizing chlorine-35 (³⁵Cl) nuclei using solid-state NMR.
- To measure short internuclear distances between carbon-13 (¹³C) and ³⁵Cl atoms.
- To quantify the influence of quadrupolar interactions on Nuclear Magnetic Resonance (NMR) experiments.
Main Methods:
- Utilized rotational-echo adiabatic passage double-resonance (RE(AP)DOR) to measure distances.
- Employed 10% uniformly labeled ¹³C L-tyrosine·HCl and natural abundance Glycine·HCl as model systems.
- Developed a method to plot dephasing curves in a 3D chart, incorporating dephasing time and quadrupolar interaction strength.
- Simulated experimental data using generated REDOR/REAPDOR curves derived from numerical investigations.
Main Results:
- Successfully measured distances shorter than 3.8 Å between ¹³C and ³⁵Cl atoms.
- Quantified the effect of quadrupolar interaction on the REDOR/REAPDOR experiment.
- Demonstrated a method to fit the influence of quadrupolar interaction on the dipolar dephasing curve using a polynomial function.
- Generated simulated REDOR/REAPDOR curves that accurately represent experimental data.
Conclusions:
- Solid-state NMR, specifically RE(AP)DOR, is effective for determining short ¹³C–³⁵Cl distances.
- The study provides a framework for understanding and mitigating the effects of quadrupolar interactions in such NMR experiments.
- This methodology enhances the capability of NMR spectroscopy for detailed structural analysis of molecules containing chloride.
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