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Double Negatively Curved C 70 Growth through a Heptagon‐Involving Pathway
Author(s) -
Zhong YuanYuan,
Chen ZuoChang,
Du Peng,
Cui CunHao,
Tian HanRui,
Shi XiangMei,
Deng ShunLiu,
Gao Fei,
Zhang Qianyan,
Gao CongLi,
Zhang Xin,
Xie SuYuan,
Huang RongBin,
Zheng LanSun
Publication year - 2019
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201902154
Subject(s) - cluster (spacecraft) , chemistry , fullerene , crystallography , carbon fibers , curvature , homo/lumo , stereochemistry , materials science , molecule , geometry , organic chemistry , mathematics , composite number , computer science , composite material , programming language
All previously reported C 70 isomers have positive curvature and contain 12 pentagons in addition to hexagons. Herein, we report a new C 70 species with two negatively curved heptagon moieties and 14 pentagons. This unconventional heptafullerene[70] containing two symmetric heptagons, referred to as dihept‐C 70 , grows in the carbon arc by a theoretically supported pathway in which the carbon cluster of a previously reported C 66 species undergoes successive C 2 insertion via a known heptafullerene[68] intermediate with low energy barriers. As identified by X‐ray crystallography, the occurrence of heptagons facilitates a reduction in the angle of the π‐orbital axis vector in the fused pentagons to stabilize dihept‐C 70 . Chlorination at the intersection of a heptagon and two adjacent pentagons can greatly enlarge the HOMO–LUMO gap, which makes dihept‐C 70 Cl 6 isolable by chromatography. The synthesis of dihept‐C 70 Cl 6 offers precious clues with respect to the fullerene formation mechanism in the carbon‐clustering process.