title: D2d(23)-C84versus Sc2C2@D2d(23)-C84: Impact of Endohedral Sc2C2Doping on Chemical Reactivity in the Photolysis of Diazirine.
abstract: We compared the chemical reactivity of D2d(23)-C84and that of Sc2C2@D2d(23)-C84, both having the same carbon cage geometry, in the photolysis of 2-adamantane-2,3'-[3H]-diazirine, to clarify metal-atom doping effects on the chemical reactivity of the carbon cage. Experimental and computational studies have revealed that the chemical reactivity of the D2d(23)-C84carbon cage is altered drastically by endohedral Sc2C2doping. The reaction of empty D2d(23)-C84with the diazirine under photoirradiation yields two adamantylidene (Ad) adducts. NMR spectroscopic studies revealed that the major Ad monoadduct (C84(Ad)-A) has a fulleroid structure and that the minor Ad monoadduct (C84(Ad)-B) has a methanofullerene structure. The latter was also characterized using X-ray crystallography. C84(Ad)-A is stable under photoirradiation, but it interconverted to C84(Ad)-B by heating at 80 °C. In contrast, the reaction of endohedral Sc2C2@D2d(23)-C84with diazirine under photoirradiation affords four Ad monoadducts (Sc2C2@C84(Ad)-A, Sc2C2@C84(Ad)-B, Sc2C2@C84(Ad)-C, and Sc2C2@C84(Ad)-D). The structure of Sc2C2@C84(Ad)-C was characterized using X-ray crystallography. Thermal interconversion of Sc2C2@C84(Ad)-A and Sc2C2@C84(Ad)-B to Sc2C2@C84(Ad)-C was also observed. The reaction mechanisms of the Ad addition and thermal interconversion were elucidated from theoretical calculations. Calculation results suggest that C84(Ad)-B and Sc2C2@C84(Ad)-C are thermodynamically favorable products. Their different chemical reactivities derive from Sc2C2doping, which raises the HOMO and LUMO levels of the D2d(23)-C84carbon cage.
authors.affiliation: Department of Chemistry, Tokyo Gakugei University , Tokyo 184-8501, Japan.
authors.forename: Michio
authors.initials: M
authors.lastname: Yamada
authors.affiliation: Life Science Center of Tsukuba Advanced Research Alliance, University of Tsukuba , Ibaraki 305-8577, Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Tanabe
authors.affiliation: Institute for Chemical Physics & Department of Chemistry, State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University , Xi'an 710049, China.
authors.forename: Jing-Shuang
authors.initials: JS
authors.lastname: Dang
authors.affiliation: Life Science Center of Tsukuba Advanced Research Alliance, University of Tsukuba , Ibaraki 305-8577, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Sato
authors.affiliation: Life Science Center of Tsukuba Advanced Research Alliance, University of Tsukuba , Ibaraki 305-8577, Japan.
authors.forename: Naomi
authors.initials: N
authors.lastname: Mizorogi
authors.affiliation: Life Science Center of Tsukuba Advanced Research Alliance, University of Tsukuba , Ibaraki 305-8577, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Hachiya
authors.affiliation: Department of Chemistry, Tokyo Gakugei University , Tokyo 184-8501, Japan.
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Suzuki
authors.affiliation: Life Science Center of Tsukuba Advanced Research Alliance, University of Tsukuba , Ibaraki 305-8577, Japan.
authors.forename: Tsuneyuki
authors.initials: T
authors.lastname: Abe
authors.affiliation: Life Science Center of Tsukuba Advanced Research Alliance, University of Tsukuba , Ibaraki 305-8577, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kurihara
authors.affiliation: Department of Chemistry, Tokyo Gakugei University , Tokyo 184-8501, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Maeda
authors.affiliation: Institute for Chemical Physics & Department of Chemistry, State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University , Xi'an 710049, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Life Science Center of Tsukuba Advanced Research Alliance, University of Tsukuba , Ibaraki 305-8577, Japan.|Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials Science, Heilongjiang University , Harbin 150080, China.
authors.forename: Yongfu
authors.initials: Y
authors.lastname: Lian
authors.affiliation: Fukui Institute for Fundamental Chemistry, Kyoto University , Kyoto 606-8103, Japan.
authors.forename: Shigeru
authors.initials: S
authors.lastname: Nagase
authors.affiliation: Department of Chemistry, Tokyo Gakugei University , Tokyo 184-8501, Japan.|Life Science Center of Tsukuba Advanced Research Alliance, University of Tsukuba , Ibaraki 305-8577, Japan.|Foundation for Advancement of International Science, Ibaraki 305-0821, Japan.
authors.forename: Takeshi
authors.identifier: 0000-0002-4073-4354
authors.initials: T
authors.lastname: Akasaka