title: Radical coupling reaction of paramagnetic endohedral metallofullerene La@C82.
abstract: The thermal reaction of La@C(82)(C(2v)) with 3-triphenylmethyl-5-oxazolidinone (1) in toluene affords benzyl monoadducts La@C(82)(C(2v))(CH(2)C(6)H(5)) (2a-2d). The same monoadducts are also obtained by the photoirradiation of La@C(82)(C(2v)) in toluene without the existence of 1. These reactions are applicable to paramagnetic metallofullerenes, such as La@C(82)(C(s)) and Ce@C(82)(C(2v)). The photoirradiation of La@C(82)(C(2v)) in 1,2-dichlorobenzene in the presence of alpha,alpha,2,4-tetrachlorotoluene also affords the monoadducts La@C(82)(C(2v))(CHClC(6)H(3)Cl(2)) (3a-3d). The monoadducts are fully characterized by spectroscopic analyses. Single-crystal X-ray structure analysis for 3d reveals the unique structure. Theoretical calculations show that the cage carbons having high spin densities are selectively attacked by radical species to form the monoadducts linked by a carbon-carbon single bond. The thermal reaction of La@C(82)(C(2v)) with 1 in benzene affords metallofulleropyrrolidine La@C(82)(C(2v))(C(2)H(4)NCPh(3)) (5), unlike the reaction in toluene.
authors.affiliation: Center for Tsukuba Advanced Research Alliance, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan.
authors.forename: Yuta
authors.initials: Y
authors.lastname: Takano
authors.forename: Akinori
authors.initials: A
authors.lastname: Yomogida
authors.forename: Hidefumi
authors.initials: H
authors.lastname: Nikawa
authors.forename: Michio
authors.initials: M
authors.lastname: Yamada
authors.forename: Takatsugu
authors.initials: T
authors.lastname: Wakahara
authors.forename: Takahiro
authors.initials: T
authors.lastname: Tsuchiya
authors.forename: Midori O
authors.initials: MO
authors.lastname: Ishitsuka
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Maeda
authors.forename: Takeshi
authors.initials: T
authors.lastname: Akasaka
authors.forename: Tatsuhisa
authors.initials: T
authors.lastname: Kato
authors.forename: Zdenek
authors.initials: Z
authors.lastname: Slanina
authors.forename: Naomi
authors.initials: N
authors.lastname: Mizorogi
authors.forename: Shigeru
authors.initials: S
authors.lastname: Nagase
mesh_terms: D001554:Benzene / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D018360:Crystallography, X-Ray; D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals / Q000737:chemistry; D037741:Fullerenes / Q000737:chemistry* / Q000302:isolation & purification; D007811:Lanthanum / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D010084:Oxidation-Reduction; D055668:Photochemical Processes; D012997:Solvents; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013055:Spectrophotometry, Infrared
chemical_list: D005609:Free Radicals; D037741:Fullerenes; D012997:Solvents; D007811:Lanthanum; D001554:Benzene