title: X-ray observation of a helium atom and placing a nitrogen atom inside He@C60 and He@C70.
abstract: Single crystal X-ray analysis has been used as a powerful method to determine the structure of molecules. However, crystallographic data containing helium has not been reported, owing to the difficulty in embedding helium into crystalline materials. Here we report the X-ray diffraction study of He@C60 and the clear observation of a single helium atom inside C60. In addition, the close packing of a helium atom and a nitrogen atom inside fullerenes is realized using two stepwise insertion techniques, that is, molecular surgery to synthesize the fullerenes encapsulating a helium atom, followed by nitrogen radio-frequency plasma methods to generate the fullerenes encapsulating both helium and nitrogen atoms. Electron spin resonance analysis reveals that the encapsulated helium atom has a small but detectable influence on the electronic properties of the highly reactive nitrogen atom coexisting inside the fullerene, suggesting the potential usage of helium for controlling electronic properties of reactive species.
authors: Institute for Chemical Research, Kyoto University, Kyoto 611-0011, Japan.
authors: Yuta
authors: Y
authors: Morinaka
authors: Satoru
authors: S
authors: Sato
authors: Atsushi
authors: A
authors: Wakamiya
authors: Hidefumi
authors: H
authors: Nikawa
authors: Naomi
authors: N
authors: Mizorogi
authors: Fumiyuki
authors: F
authors: Tanabe
authors: Michihisa
authors: M
authors: Murata
authors: Koichi
authors: K
authors: Komatsu
authors: Ko
authors: K
authors: Furukawa
authors: Tatsuhisa
authors: T
authors: Kato
authors: Shigeru
authors: S
authors: Nagase
authors: Takeshi
authors: T
authors: Akasaka
authors: Yasujiro
authors: Y
authors: Murata