title: An azine-linked covalent organic framework.
abstract: Condensation of hydrazine with 1,3,6,8-tetrakis(4-formylphenyl)pyrene under solvothermal conditions yields highly crystalline two-dimensional covalent organic frameworks. The pyrene units occupy the vertices and the diazabutadiene (-C═N-N═C-) linkers locate the edges of rohmbic-shaped polygon sheets, which further stack in an AA-stacking mode to constitute periodically ordered pyrene columns and one-dimensional microporous channels. The azine-linked frameworks feature permanent porosity with high surface area and exhibit outstanding chemical stability. By virtue of the pyrene columnar ordering, the azine-linked frameworks are highly luminescent, whereas the azine units serve as open docking sites for hydrogen-bonding interactions. These synergestic functions of the vertices and edge units endow the azine-linked pyrene frameworks with extremely high sensitivity and selectivity in chemosensing, for example, the selective detection of 2,4,6-trinitrophenol explosive. We anticipate that the extension of the present azine-linked strategy would not only increase the structural diversity but also expand the scope of functions based on this highly stable class of covalent organic frameworks.
authors.affiliation: Department of Materials Molecular Science, Institute for Molecular Science, National Institutes of Natural Sciences , 5-1 Higashiyama, Myodaiji, Okazaki 444-8787, Japan.
authors.forename: Sasanka
authors.initials: S
authors.lastname: Dalapati
authors.forename: Shangbin
authors.initials: S
authors.lastname: Jin
authors.forename: Jia
authors.initials: J
authors.lastname: Gao
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Xu
authors.forename: Atsushi
authors.initials: A
authors.lastname: Nagai
authors.forename: Donglin
authors.initials: D
authors.lastname: Jiang