An Nmr Study of the Occupation of C60 Interstitial Sites by Oxygen Molecules

1992 ◽  
Vol 270 ◽  
Author(s):  
Roger A. Assink ◽  
Douglas A. Loy ◽  
James E. Schirber ◽  
Bruno Morosin
Keyword(s):  
Ambient Pressure ◽  
Primary Resonance ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Nmr Study ◽  
Minor Peak ◽  
Fermi Contact ◽  
Angle Spinning ◽  
A Minor ◽  
C Nmr

ABSTRACTThe 13C NMR of FCC C60 under magic angle spinning (MAS) conditionsyields linewidths on the order of 1 Hz at fields of 4.7 T. The spectrum consists of a primary resonance at 143.7 ppm and a minor peak shifted 0.7 ppm downfield. The intensity of the minor resonance relative to the primary resonance was found to vary from 0.6 to 5.5 % depending on the sample history. The downfield shift obeys Curie's law and isattributed to the Fermi contact coupling interaction between paramagnetic oxygen molecules and all 60 carbon atoms of rapidly rotating adjacent C60 molecules. Exposure of the sample to 1 kbar oxygen for 1 3/4 hours resulted in a spectrum of 7 evenly spaced resonances corresponding to 0 to 6 of the adjacent octahedral interstitial sites being filled with oxygen molecules. At ambient pressure, the oxygen diffused out of the lattice on time scales ranging from hours to days.

Intercalation of molecular species into the interstitial sites of fullerene

1992 ◽  
Vol 7 (8) ◽  
pp. 2136-2143 ◽  
Author(s):  
Roger A. Assink ◽  
James E. Schirber ◽  
Douglas A. Loy ◽  
Bruno Morosin ◽  
Gary A. Carlson
Keyword(s):  
Molecular Species ◽  
Room Temperature ◽  
Primary Resonance ◽  
Magic Angle Spinning ◽  
Hydrogen Gas ◽  
Magic Angle ◽  
Hydrogen Molecules ◽  
Fcc Lattice ◽  
Angle Spinning ◽  
A Minor

Molecular species were found to diffuse readily into the octahedral interstitial sites of the fcc lattice of C60. The 13C NMR spectrum of C60 under magic angle spinning (MAS) conditions consisted of a primary resonance at 143.7 ppm and a minor peak shifted 0.7 ppm downfield. The downfield shift obeys Curie's law and is attributed to the Fermi-contact interaction between paramagnetic oxygen molecules and all 60 carbon atoms of rapidly rotating adjacent C60 molecules. Exposure of C60 to 1 kbar oxygen for 1.75 h at room temperature resulted in a spectrum of seven evenly spaced resonances corresponding to the filling of 0 to 6 of the adjacent octahedral interstitial sites with oxygen molecules. The distribution of site occupancies about a C60 molecule provided evidence that the intercalation process is controlled by diffusion kinetics. Exposure to 0.14 kbar hydrogen gas at room temperature for 16 h filled a substantial fraction of the interstitial sites of C60 and C70 with hydrogen molecules.

Magic Angle Spinning NMR Study on Inversion Behavior and Vacancy Disorder in Alumina-Rich Spinel

2018 ◽  
Vol 57 (14) ◽  
pp. 8390-8395 ◽  
Author(s):  
Bingtian Tu ◽  
He Zhang ◽  
Hao Wang ◽  
Weimin Wang ◽  
Zhengyi Fu
Keyword(s):  
Magic Angle Spinning ◽  
Magic Angle ◽  
Nmr Study ◽  
Angle Spinning

Phosphorus-31 chemical shieldings in a fused cis-1,2,3-benzothiadiphosphole: a dipolar NMR study

1992 ◽  
Vol 70 (4) ◽  
pp. 1229-1235 ◽  
Author(s):  
Gang Wu ◽  
Roderick E. Wasylishen ◽  
William P. Power ◽  
Graziano Baccolini
Keyword(s):  
Line Shape ◽  
Magic Angle Spinning ◽  
Pair Approximation ◽  
Magic Angle ◽  
Single Bond ◽  
Chemical Shielding ◽  
Spin Pair ◽  
Nmr Study ◽  
Shielding Tensors ◽  
Angle Spinning

Phosphorus-31 NMR static powder spectra and high-resolution magic angle spinning spectra have been obtained for a new heterocyclic compound, cis-2,10-dimethyl[1,2,3]benzothiadiphospholo[2,3b][1,2,3]benzothiadiphosphole (1), which contains a P(III)—P(III) single bond. The homonuclear 31P–31P dipolar interaction manifests itself in both the magic angle spinning spectra and the non-spinning line shape. Under the AX spin pair approximation, analysis of the spinning sidebands in the MAS experiment yields a full characterization of the two 31P chemical shielding tensors. This approximation is confirmed by the exact powder line shape simulation for a homonuclear spin pair. Analysis of the dipolar subspectra also yields the absolute sign of 1J(P,P), which is found to be negative. Keywords: phosphorus–phosphorus single bond, chemical shielding tensors, dipolar NMR, MAS, static line shape.

A 13C and 15N nuclear magnetic resonance study of solid ammonium thiocyanate

1987 ◽  
Vol 65 (5) ◽  
pp. 941-946 ◽  
Author(s):  
Ross M. Dickson ◽  
Michael S. McKinnon ◽  
James F. Britten ◽  
Roderick E. Wasylishen
Keyword(s):  
Ammonium Thiocyanate ◽  
Nuclear Magnetic Resonance Study ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Chemical Shielding ◽  
X Ray ◽  
Shielding Constants ◽  
Angle Spinning ◽  
Good Agreement ◽  
C Nmr

The static 13C nmr powder pattern for solid ammonium thiocyanate is analyzed to obtain the 13C chemical shielding anisotropy, 321 ± 7 ppm, and the 13C–14N dipolar splitting, 1295 ± 25 Hz. Slow magic angle spinning 15N nmr experiments are analyzed to obtain a nitrogen chemical shielding anisotropy of 415 ± 15 ppm. The 13C–14N dipolar splitting leads to an effective C—N bond length of 1.19 ± 0.01 Å, in good agreement with the value of 1.176 Å reported from accurate X-ray and neutron crystallographic studies. In solid NH4NCS absolute values of the average shielding constants [Formula: see text] and ct[Formula: see text] are 52 and 34 ppm, respectively. Comparison of calculated and observed [Formula: see text] values indicates that intermolecular interactions decrease the 13C and 15N shielding constants by approximately 10 and 30 ppm, respectively.

Solid-state 17O NMR Study of Small Biological Compounds

2007 ◽  
Vol 62 (11) ◽  
pp. 1422-1432 ◽  
Author(s):  
Kazuhiko Yamada ◽  
Tadashi Shimizu ◽  
Yoshida Mitsuru ◽  
Miwako Asanuma ◽  
Masataka Tansho ◽  
...  
Keyword(s):  
Solid State ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Multiple Quantum ◽  
Peptide Analysis ◽  
17O Nmr ◽  
Nmr Study ◽  
Biological Compounds ◽  
Nmr Tensors ◽  
Angle Spinning

We present a systematic experimental and theoretical investigation of the oxygen chemical shielding and electric-field-gradient tensors in polycrystalline amino acids and a peptide. Analysis of the 17O magic-angle-spinning (MAS), multiple-quantum MAS, and stationary nuclear magnetic resonance (NMR) spectra yield the magnitudes and the relative orientations between the two NMR tensors. The obtained 17O NMR parameters are sensitive to the hydrogen bond environments. We also demonstrate that solid-state 17O NMR is potentially useful for studying the secondary structures of peptides and proteins.

Kinetics of the hydration reactions in the cement paste with mechanochemically modified cement 29Si magic-angle-spinning NMR study

1999 ◽  
Vol 29 (10) ◽  
pp. 1575-1581 ◽  
Author(s):  
Karin Johansson ◽  
Cecilia Larsson ◽  
Oleg N. Antzutkin ◽  
Willis Forsling ◽  
Hanumantha Rao Kota ◽  
...  
Keyword(s):  
Cement Paste ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Nmr Study ◽  
Angle Spinning ◽  
Kinetics Of

13C Magic-Angle-Spinning NMR Study of the Electronic Properties of theAC60Polymers(A=K,Rb,Cs)

1996 ◽  
Vol 76 (16) ◽  
pp. 2922-2925 ◽  
Author(s):  
H. Alloul ◽  
V. Brouet ◽  
E. Lafontaine ◽  
L. Malier ◽  
L. Forro
Keyword(s):  
Electronic Properties ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Nmr Study ◽  
Angle Spinning

A high resolution1H magic angle spinning NMR study of a high-Mr subunit of wheat glutenin

Biopolymers ◽  
2000 ◽  
Vol 58 (1) ◽  
pp. 33-45 ◽  
Author(s):  
Enrica Alberti ◽  
Eberhard Humpfer ◽  
Manfred Spraul ◽  
Simon M. Gilbert ◽  
Arthur S. Tatham ◽  
...  
Keyword(s):  
Magic Angle Spinning ◽  
Magic Angle ◽  
Nmr Study ◽  
Angle Spinning
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