Ordered Van der Waals Hetero-nanoribbon from Pressure-Induced Topochemical Polymerization of Azobenzene
Peijie Zhang, Dexiang Gao, Xingyu Tang, Xin Yang, Haiyan Zheng, Yida Wang, Xuan Wang, Jingqin Xu, Zijia Wang, Jie Liu, Xiaoge Wang, Jing Ju, Mingxue Tang, Xiao Dong, Kuo Li, Ho‐kwang Mao
Abstract
Pressure-induced topochemical polymerization of molecular crystals with various stackings is a promising way to synthesize materials with different co-existing sub-structures. Here, by compressing the azobenzene crystal containing two kinds of intermolecular stacking, we synthesized an ordered van der Waals carbon nanoribbon (CNR) heterostructure in one step. Azobenzene polymerizes via a [4 + 2] hetero-Diels–Alder (HDA) reaction of phenylazo-phenyl in layer A and a para -polymerization reaction of phenyl in layer B at 18 GPa, as evidenced by in situ Raman and IR spectroscopies, X-ray diffraction, as well as gas chromatography–mass spectrometry and the solid-state nuclear magnetic resonance of the recovered products. The theoretical calculation shows that the obtained CNR heterostructure has a type II (staggered) band gap alignment. Our work highlights a high-pressure strategy to synthesize bulk CNR heterostructures.