Guillaume Povie, Yasutomo Segawa, Taishi Nishihara, Yuhei Miyauchi, and Kenichiro Itami
J. Am. Chem. Soc. 2018, DOI: 10.1021/jacs.8b06842
The synthesis and X-ray crystal structure of the first member of the carbon nanobelt family is reported. carbon nanobelt (CNB) was originally obtained from a nickel-mediated reductive coupling reaction of a dodecabrominated macrocyclic precursor, albeit only in 1% yield. The present article reports on the development of this synthetic strategy and its extension to the preparation of the  and CNB analogues. In particular, our extensive investigations on the final belt-forming, nickel-mediated reaction led to the development of a new ligand system that provides CNB in up to 7% yield, contributing the commercialization of CNB. The belt structures of , , and CNB were characterized by NMR, UV-vis, and Raman spectroscopy as well as mass spectrometry and X-ray crystallography. The fluorescence of the CNBs in solution displayed a remarkable dependence on the ring size, ranging from a broad red emission (CNB) to a narrow-band blue emission (CNB), while both features are observed for CNB.