title: First isomers of pristine C104 fullerene structurally confirmed as chlorides, C104(258)Cl16 and C104(812)Cl24.
abstract: Isolation and characterization of very large fullerenes is hampered by a drastic decrease of their content in fullerene soot with increasing fullerene size and a simultaneous increase of the number of possible IPR (Isolated Pentagon Rule) isomers. In the present work, fractions containing mixtures of C102 and C104 were isolated in very small quantities (several dozens of micrograms) by multi-step recycling HPLC from an arc-discharge fullerene soot. Two such fractions were used for chlorination with a VCl4/SbCl5 mixture in glass ampoules at 350-360 °C. The resulting chlorides were investigated by single-crystal X-ray diffraction using synchrotron radiation. By this means, two IPR isomers of C104 , numbers 258 and 812 (of 823 topologically possible isomers), have been confirmed for the first time as chlorides, C1 -C104(258)Cl16 and D2-C104 (812)Cl24, respectively, while an admixture of C2 -C104(811)Cl24 was assumed to be present in the latter chloride. DFT calculations showed that pristine C104(812) belongs to rather stable C104 cages, whereas C104(258) is much less stable.
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, University of Science and Technology of China, Hefei 230026 (China). sfyang@ustc.edu.cn.
authors.forename: Shangfeng
authors.initials: S
authors.lastname: Yang
authors.forename: Tao
authors.initials: T
authors.lastname: Wei
authors.forename: Erhard
authors.initials: E
authors.lastname: Kemnitz
authors.forename: Sergey I
authors.initials: SI
authors.lastname: Troyanov
keywords: C104 isomers; chlorination; density functional calculations; fullerenes; structure elucidation