X-ray diffraction patterns for a solid sample of Ce@C 82 that contains a mixture of two isomers, I and II, can be indexed in a face-centered cubic lattice with a lattice constant of 15.88͑5͒ Å, while x-ray diffraction patterns for Ce@C 82 isomer I alone indicate a simple cubic lattice with a lattice constant of 15.78͑1͒ Å. Rietveld refinement for the x-ray diffraction pattern of the latter, Ce@C 82 isomer I, has been carried out with a space group of Pa3 . Thin films of Ce@C 82 were first prepared by thermal deposition under ϳ10 Ϫ7 Torr. The Raman spectra for these thin films show a peak ascribable to a Ce-C 82 cage-stretching mode at ϳ160 cm Ϫ1 , implying that the valence of Ce in this structure is ϩ3. This valence of ϩ3 is supported by Ce L III -edge XANES for a thin film of Ce@C 82 . Furthermore, the local structure around the Ce ion could be determined by Ce L III -edge EXAFS for a thin-film. Transport properties of a thin film of Ce@C 82 have been studied by a four-probe method, and these demonstrate a semiconducting behavior with a small gap of 0.4 eV.

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Ambipolar field-effect transistor (FET) device was fabricated with heterostructure of thin films of C 60 and pentacene. Three types of device structures in the C 60 /pentacene heterostructure FET device were studied in order to realize the best ambipolar properties. In the middle-contact type FET device of C 60 and pentacene, the mobility in p-channel operation was estimated to be 6.8 ϫ 10 −2 cm 2 V −1 s −1 , while the in n-channel operation was 1.3ϫ 10 −3 cm 2 V −1 s −1. This ambipolar FET device is available for a practical building-block to form CMOS integrated circuits with low-power consumption, good-noise margins, and ease of design.

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Fullerene field-effect transistors (FETs) were fabricated with thin films of C84, which showed n-channel normally-on depletion-type FET characteristics. The C84 FET device exhibited the highest mobility, μ, of 2.1×10−3 cm2 V−1 s−1 among normally-on fullerene FETs. The carrier transport of this FET device can be interpreted as thermally activated hopping transport. Carrier type (n-channel) and transport mechanism (hopping) reflect the electronic properties of the C84 molecule.

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A new antibiotic with hypolipidemic activity, ascofuranone, C23H29CIO5, and related substance, ascofuranol, C23H31CIO5,were isolated from the filter cake of the fermented broth of Ascochyta viciae Libert, an ascochlorin-producing fungus, and their structures were elucidated. They possess 3-substituted-5-chloro-orcylaldehyde moiety with novel sesquiterpenyl side chains. In our screening for hypolipidemic agents from microorganisms, new prenylphenols1 ' , ascofuranone2) 00 and ascofuranol (II), were isolated from an ascochlorin-producing fungus, Ascochyta viciae Libert3 '45. In this paper the isolation and structure of these novel prenylphenols are described.

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