@article{e41e9a29ad8d4ff19afbf0e7130c47f9,
title = "Structure of [60]fullerene with amobile lithium cation inside",
abstract = "The structure of crystalline [60]fullerene with a lithium cation inside (Li+@C60) was determined by synchrotron radiation X-ray diffraction measurements to understand the electrostatic and thermal properties of the encapsulated Li+ cation. Although the C60 cages show severe orientation disorder in [Li+@C60](TFPB-)·C4H10O and [Li+@C60](TFSI-)·CH2Cl2, the Li+ cations are rather ordered at specific positions by electrostatic interactions with coordinated anions outside the C60 cage. The Li+@C60 molecules in [Li+@C60](ClO4 -) with a rock-salt-type cubic structure are fully disordered with almost uniform spherical shell charge densities even at 100K by octahedral coordination of ClO4 - tetrahedra and show no orientation ordering, unlike [Li+@C60](PF6-) and pristine C60. Single-bonded (Li+@C60 -)2 dimers in [Li+@C60 -](NiOEP)·CH2Cl2 are thermally stable even at 400K and form Li+-C bonds which are shorter than Li+-C bonds in [Li+@C60](PF6-) and suppress the rotational motion of the Li+ cations.",
keywords = "Endohedral metallofullerene, Fullerene, Li@C, Synchrotron radiation, X-ray crystal structure analysis",
author = "Shinobu Aoyagi and Kazuhira Miwa and Hiroshi Ueno and Hiroshi Okada and Yutaka Matsuo and Ken Kokubo",
note = "Funding Information: Data accessibility. The CIFs are available as the electronic supplementary material and from the Cambridge Crystallographic Data Centre (CCDC) (www.ccdc.cam.ac.uk/structures) with deposition numbers 1826722, 1826723 and 1826724. Authors{\textquoteright} contributions. S.A. carried out the SR XRD experiments and crystal structure analyses, and wrote the manuscript. K.M. carried out the crystallization and crystal structure analysis. H.U. and H.O. carried out the anion exchange, electrochemical reduction and crystallization. Y.M. and K.K. supervised and conducted the sample preparations and chemical analyses. All authors gave final approval for publication. Competing interests. We declare we have no competing interests. Funding. This work was financially supported by The Mitsubishi Foundation and The Murata Science Foundation. Acknowledgements. The synchrotron radiation experiments were performed at SPring-8 with the approval of the Japan Synchrotron Radiation Research Institute (JASRI) (proposal nos. 2013A0100, 2013B0100, 2015A0100, 2017A1206 and 2017A1739). S.A. thanks Mr Y. Yokoi, Ms Y. Nakahira and Dr K. Sugimoto for their help with the experiments. Publisher Copyright: {\textcopyright} 2018 The Authors.",
year = "2018",
month = jul,
day = "1",
doi = "10.1098/rsos.180337",
language = "English",
volume = "5",
journal = "Royal Society Open Science",
issn = "2054-5703",
publisher = "The Royal Society",
number = "7",
}