Disproportionation of photoexcited C{sub 60}

Journal Article · Wed May 15 04:00:00 EDT 1996 · Journal of the American Chemical Society

DOI:https://doi.org/10.1021/ja952640l· OSTI ID:263233

Yang, C C; Hwang, K C ^[1]

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1. National Tsing Hua Univ., Hsinchu (Taiwan, Province of China)

Irradiation of C{sub 60}-toluene solution at room temperature affords two ESR bands with g and {Delta}H{sub pp} values of (2.0013, 0.5 G) and (2.0024, 0.75 G), respectively. In the presence of 6% methanol or 12% benzonitrile, the latter band disappears completely. Below 200 K, only the former bank was observed. They were assigned to be {sup 3}C{sub 60} and C{sub 60}{sup .+}, respectively. In the presence of tetraphenylphosphonium tetraphenylborate, the g value of the C{sub 60}{sup .+} cation radical shifts to 2.0006, and an additional broad band of g = 1.9992 and {Delta}H{sub pp}=30 G was observed. Upon cooling, the line width of this new band drops from 30 G at 300 K to 4 G at 77 K. This new band was assigned to be the C{sub 60}{sup .-} anion radical according to its characteristic behavior. At room temperature, photolysis causes the C{sub 60}-toluene solution`s color to turn from purple to brown, and then brown precipitates formed. Desorption chemical ionization (DCI) mass analysis of the brown precipitates indicates the formation of C{sub 60}.H{sub n}(tolyl){sub n} (n = 1-4) adducts. The formation of C{sub 60}{sup .+} and C{sub 60}{sup .-} was rationalized in terms of disproportionation of two {sup 3}C{sub 60}. The brown precipitates were due to the chemical reaction between the C{sub 60}{sup .+} cation radical and the solvent molecules, which rationalizes the `photodegradation` of fullerene as reported in literature. 38 refs., 5 figs.

• OSTI ID: 263233
• Journal Information: Journal of the American Chemical Society, Journal Name: Journal of the American Chemical Society Journal Issue: 19 Vol. 118; ISSN JACSAT; ISSN 0002-7863
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
40 CHEMISTRY
ANIONS
DISSOCIATION
ELECTRON SPIN RESONANCE
FULLERENES
IRRADIATION
PHOTOCHEMICAL REACTIONS
PHOTOCONDUCTIVITY
POLYMERIZATION
RADICALS
SOLUTIONS
TOLUENE