Skip to main content Accessibility help
×
Home

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

  • Roger A. Assink (a1), Douglas A. Loy (a1), James E. Schirber (a1) and Bruno Morosin (a1)

Abstract

The 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.

Copyright

References

Hide All
1. Kroto, H. W., Heath, J. R., O'Brien, S. C., Curl, R. F., Smalley, R. E., Nature 318, 162 (1985).
2. Kratschmer, W., Lamb, L. D., Fostiropoulos, K., Huffman, D. R., Nature 347, 354 (1990).
3. (A) The sample was purified by chromatography (Allemand, P.-M. et al. , J. Am. Chem. Soc. 113, 1050 (1991)) from toluene soluble soot purchased from Texas Fullerene Corp, Houston, TX. This material was then annealed for 2 hrs at 225 C. Annealing sharpened the x-ray powder diffraction lines and removed the stacking faults and defects contributing to the “foot” character of the (111) line. (B) Additional material was purchased as 99.5 % pure C60 from Texas Fullerene Corp. This sample as-received showed broad x-ray lines which became sharp upon annealing at 225 C with no evidence of a "foot" on the (111) line. Identical NMR results were obtained with this material.
4. Creegan, K. M. et al. , poster presented at the MRS Fall Meeting, Boston, MA, 2-6 December 1991.
5. Jesson, J. P. in The Paramagnetic Shift, Mar, G. N. La, Horrocks, W. DeW. Jr., and Holm, R. H., Eds. (Academic Press, New York, 1973) pp. 152.
6. Tycko, R. et al. , J. Phys. Chem. 95, 518 (1991); C. S. Yannoni, R. D. Johnson, G. Meijer, D. S. Bethune, J. R. Salem, J. Phys. Chem. 95, 9 (1991).
7. Tycko, R. et al. , Phys. Rev. Lett. 67, 1886 (1991).
8. Heiney, P. et al. , Phys. Rev. Lett. 66, 2911 (1991); S. Liu, Y. Lu, M. M. Kappes, J. A. Ibers, Science 254, 408 (1991); W. I. F. David et al., Nature 353, 147 (1991).
9. Pauling, L., The Nature of the Chemical Bond (Cornell University Press, 1960) pp. 259–64.
10. Assink, R. A., Schirber, J. E., Loy, Douglas A., Morosin, B. and Carlson, G. A., J. Mater. Res., accepted for publication.

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

  • Roger A. Assink (a1), Douglas A. Loy (a1), James E. Schirber (a1) and Bruno Morosin (a1)

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed