title: A structural diagnostics diagram for metallofullerenes encapsulating metal carbides and nitrides.
abstract: Systematic structural studies of 24 different kinds of endohedral metallofullerenes, M(x)C(2n) (M = La, Y, Sc, Lu, Ti, Eu, Er, Hf, Sc(3)N; 34 ≤ n ≤ 43), as 1:1 cocrystals with solvent toluene molecules have been carried out using synchrotron radiation powder diffraction. Thirteen of the 24 molecular structures, including five metal carbides, one metal nitride endohedral fullerene, and one hollow fullerene, have been determined by a combination of the maximum entropy method and Rietveld refinement of the X-ray diffraction data obtained. We have found that the volume for one fullerene and one toluene molecule depends linearly on the number of carbon atoms in the fullerene cage. Fifteen different kinds of metal carbide endohedral fullerenes have been identified, which can be structurally characterized from the obtained lattice constants using only this linear dependence. The linear dependence found in the present study provides a metallofullerene diagnostics diagram that may have universal importance for structural characterization of the so-called cluster endohedral fullerenes.
authors.affiliation: RIKEN SPring-8 Center, RIKEN, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan.
authors.forename: Sachiko
authors.initials: S
authors.lastname: Maki
authors.forename: Eiji
authors.initials: E
authors.lastname: Nishibori
authors.forename: Ikuya
authors.initials: I
authors.lastname: Terauchi
authors.forename: Masayuki
authors.initials: M
authors.lastname: Ishihara
authors.forename: Shinobu
authors.initials: S
authors.lastname: Aoyagi
authors.forename: Makoto
authors.initials: M
authors.lastname: Sakata
authors.forename: Masaki
authors.initials: M
authors.lastname: Takata
authors.forename: Hisashi
authors.initials: H
authors.lastname: Umemoto
authors.forename: Takashi
authors.initials: T
authors.lastname: Inoue
authors.forename: Hisanori
authors.initials: H
authors.lastname: Shinohara