Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Ring current effects
T2 - factors affecting the NMR chemical shift of molecules adsorbed on porous carbons
AU - Forse, Alexander C.
AU - Griffin, John M.
AU - Presser, Volker
AU - Gogotsi, Yury
AU - Grey, Clare P.
PY - 2014/4/10
Y1 - 2014/4/10
N2 - Nuclear magnetic resonance (NMR) spectroscopy is increasingly being used to study the adsorption of molecules in porous carbons, a process which underpins applications ranging from electrochemical energy storage to water purification. Here we present density functional theory (DFT) calculations of the nucleus-independent chemical shift (NICS) near various sp(2)-hybridized carbon fragments to explore the structural factors that may affect the resonance frequencies observed for adsorbed species. The domain size of the delocalized electron system affects the calculated NICSs, with larger domains giving rise to larger chemical shieldings. In slit pores, overlap of the ring current effects from the pore walls is shown to increase the chemical shielding. Finally, curvature in the carbon sheets is shown to have a significant effect on the NICS. The trends observed are consistent with existing NMR results as well as new spectra presented for an electrolyte adsorbed on carbide-derived carbons prepared at different temperatures.
AB - Nuclear magnetic resonance (NMR) spectroscopy is increasingly being used to study the adsorption of molecules in porous carbons, a process which underpins applications ranging from electrochemical energy storage to water purification. Here we present density functional theory (DFT) calculations of the nucleus-independent chemical shift (NICS) near various sp(2)-hybridized carbon fragments to explore the structural factors that may affect the resonance frequencies observed for adsorbed species. The domain size of the delocalized electron system affects the calculated NICSs, with larger domains giving rise to larger chemical shieldings. In slit pores, overlap of the ring current effects from the pore walls is shown to increase the chemical shielding. Finally, curvature in the carbon sheets is shown to have a significant effect on the NICS. The trends observed are consistent with existing NMR results as well as new spectra presented for an electrolyte adsorbed on carbide-derived carbons prepared at different temperatures.
KW - SOLID-STATE NMR
KW - NUCLEAR-MAGNETIC-RESONANCE
KW - CARBIDE-DERIVED CARBON
KW - ACTIVATED CARBON
KW - CURRENT DENSITIES
KW - ADSORPTION
KW - SPECTROSCOPY
KW - ELECTROLYTE
KW - STORAGE
KW - CHARGE
U2 - 10.1021/jp502387x
DO - 10.1021/jp502387x
M3 - Journal article
VL - 118
SP - 7508
EP - 7514
JO - The Journal of Physical Chemistry C
JF - The Journal of Physical Chemistry C
SN - 1932-7447
IS - 14
ER -