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Updated: Jun 13, 2026
08:48
High-Resolution Neutron Spectroscopy to Study Picosecond-Nanosecond Dynamics of Proteins and Hydration Water
Published on: April 28, 2022
Dynamics on the microsecond timescale in hydrous silicates studied by solid-state (2)H NMR spectroscopy.
John M Griffin1, Andrew J Miller, Andrew J Berry
1School of Chemistry and EaStCHEM, University of St Andrews, North Haugh, St Andrews, UKKY16 9ST.
Physical Chemistry Chemical Physics : PCCP
|May 8, 2010
Summary
Solid-state deuterium (2H) NMR reveals microsecond timescale dynamics in hydroxyl-clinohumite, a model for Earth
Area of Science:
- Geochemistry
- Solid-state NMR Spectroscopy
- Mineral Physics
Background:
- Hydroxyl-clinohumite is a synthetic mineral model for water incorporation in Earth's mantle.
- Understanding water dynamics in minerals is crucial for geodynamics.
- Deuterium (2H) NMR is a powerful tool for probing hydrogen dynamics in solids.
Purpose of the Study:
- To investigate the dynamic disorder of hydroxyl deuterons in deuterated hydroxyl-clinohumite.
- To model the incorporation of water within the Earth's mantle using solid-state NMR.
- To characterize the timescale and activation energy of deuteron exchange processes.
Main Methods:
- Solid-state (2)H NMR spectroscopy, including static and magic angle spinning (MAS) techniques.
- First-principles density functional theory (DFT) calculations of (2)H NMR parameters.
- Analysis of line broadening in variable-temperature MAS NMR experiments.
Main Results:
- Magic Angle Spinning (MAS) NMR revealed significant line broadening due to microsecond timescale motion.
- Static (2)H NMR showed minimal evidence of dynamics, similar to brucite.
- DFT calculations and dynamic models successfully reproduced observed line broadening and estimated rate constants.
- Activation energy for deuteron exchange was determined from variable-temperature experiments.
- Fluorine substitution was shown to inhibit the dynamic exchange process via hydrogen bonding.
Conclusions:
- Hydroxyl-clinohumite exhibits dynamic disorder of hydroxyl deuterons on the microsecond timescale.
- Static NMR is less sensitive to these dynamics compared to MAS NMR.
- The study provides insights into water behavior in the Earth's mantle and the influence of hydrogen bonding on dynamics.
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