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Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy
Published on: September 17, 2017
A solid-state NMR study of C(70): a model molecule for amorphous carbons
Michaël Deschamps1, Sylvian Cadars, Edouard Gilbert
1CNRS-CEMHTI, UPR 3079, 1D Avenue de la Recherche Scientifique, 45071 Orléans cedex 2, France. michael.deschamps@cnrs-orleans.fr
Solid State Nuclear Magnetic Resonance
|February 10, 2012
Summary
Solid-state Nuclear Magnetic Resonance (NMR) spectroscopy, specifically the INADEQUATE technique, was used to analyze crystallized C(70). This method reveals correlations between carbon-carbon bond angles and chemical shifts, aiding in understanding carbon material structures.
Area of Science:
- Solid-state Nuclear Magnetic Resonance (NMR) Spectroscopy
- Computational Chemistry
- Materials Science
Background:
- Nuclear Magnetic Resonance (NMR) spectroscopy is a powerful tool for determining molecular structure.
- Solid-state NMR presents challenges in spectral resolution due to broad lines and strong couplings.
- C(70) fullerene presents a complex system for NMR analysis due to its numerous carbon atoms.
Purpose of the Study:
- To demonstrate the feasibility of recording natural abundance, solid-state Magic Angle Spinning-NMR (MAS-NMR) Carbon-13 (13C) INADEQUATE spectra for crystallized C(70).
- To investigate the relationship between molecular structure and NMR chemical shifts in C(70).
- To explore the application of these findings to understanding the chemical shifts in nanoporous activated carbons.
Main Methods:
- Solid-state MAS-NMR spectroscopy using the through-bond J-coupling for magnetization transfer.
- Recording natural abundance (13)C INADEQUATE spectra of crystallized C(70).
- Density Functional Theory (DFT) calculations for predicting chemical shifts.
Main Results:
- Successful acquisition of solid-state (13)C INADEQUATE spectra for crystallized C(70).
- Observation of cross-peaks between closely spaced resonances, facilitated by high magnetic fields mitigating strong J-coupling effects.
- Excellent agreement between experimental (13)C chemical shifts and DFT calculations.
- Correlation established between average carbon-carbon-carbon (CCC) bond angles and (13)C chemical shifts.
Conclusions:
- Solid-state (13)C INADEQUATE NMR is effective for analyzing crystallized C(70).
- The observed correlation between CCC bond angles and chemical shifts provides insights into spectral dispersion.
- This approach can elucidate the structural characteristics of nanoporous activated carbons based on local planarity deviations.
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