title: Enhanced 1520 nm photoluminescence from Er3+ ions in di-erbium-carbide metallofullerenes (Er2C2)@C82 (isomers I, II, and III).
abstract: Di-erbium and di-erbium-carbide endohedral metallofullerenes with a C(82) cage such as Er(2)@C(82) (isomers I, II, and III) and (Er(2)C(2))@C(82) (isomers I, II, and III) have been synthesized and chromatographically isolated (99%). The structures of Er(2)@C(82) (I, II, III) and (Er(2)C(2))@C(82) (I, II, III) metallofullerenes are characterized by comparison with the UV-vis-NIR absorption spectra of (Y(2)C(2))@C(82) (I, II, III), where molecular symmetries of the structures are determined to be C(s), C(2v) and C(3v), respectively. Furthermore, enhanced near-infrared photoluminescence (PL) at 1520 nm from Er(3+) ions in Er(2)@C(82) (I, III) and (Er(2)C(2))@C(82) (I, III) have been observed at room temperature. The PL intensities have been shown to depend on the symmetry of the C(82) cage. In particular, the PL intensity of (Er(2)C(2))@C(82) (III) has been the strongest among the isomers of Er(2)@C(82) and (Er(2)C(2))@C(82). Optical measurements indicate that the PL properties of Er(2)@C(82) (I, II, III) and (Er(2)C(2))@C(82) (I, II, III) correlate strongly with the absorbance at 1520 nm and the HOMO-LUMO energy gap of the C(82) cage.
authors.affiliation: Department of Chemistry and Institute for Advanced Research, Nagoya University, Nagoya 464-8602, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Ito
authors.forename: Toshiya
authors.initials: T
authors.lastname: Okazaki
authors.forename: Shingo
authors.initials: S
authors.lastname: Okubo
authors.forename: Masahiro
authors.initials: M
authors.lastname: Akachi
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Ohno
authors.forename: Takashi
authors.initials: T
authors.lastname: Mizutani
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Nakamura
authors.forename: Ryo
authors.initials: R
authors.lastname: Kitaura
authors.forename: Toshiki
authors.initials: T
authors.lastname: Sugai
authors.forename: Hisanori
authors.initials: H
authors.lastname: Shinohara