A Three-Dimensional sp2 Carbon-Conjugated Covalent Organic Framework
journal contributionposted on 17.09.2021, 15:04 by Shitao Wang, Xiang-Xiang Li, Ling Da, Yaqin Wang, Zhehao Xiang, Wei Wang, Yue-Biao Zhang, Dapeng Cao
A first example of an sp2 carbon-conjugated three-dimensional (3D) covalent organic framework (COF) (BUCT-COF-4) is synthesized via the Knoevenagel condensation of the saddle-shaped aldehyde-substituted cyclooctatetrathiophene and 1,4-phenylenediacetonitrile. Ascribed to the extended π-conjugation and long-range ordered structures, BUCT-COF-4 displays high Hall electron mobility of 1.97 cm2 V–1 s–1 at room temperature. After it is doped with iodine, the material not only exhibits an enhanced electron mobility up to 2.62 cm2 V–1 s–1 in ambient air but also presents an unexpected metal-free ferromagnetic phase transition arising from the formation of aligned spins unidirectional across the whole sp2 carbon-conjugated 3D framework. This is the first report of a ferromagnetic phenomenon in 3D COF materials, which would broaden promising applications and open a new frontier in COF materials.
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range ordered structuresenhanced electron mobilitycovalent organic frameworkconjugated 3d framework2 </ sup3d cof materialscof materialsunexpected metalsynthesized viasubstituted cyclooctatetrathiopheneshaped aldehyderoom temperaturenew frontierknoevenagel condensationfirst reportfirst exampleferromagnetic phenomenonextended πconjugated threeambient airalso presents97 cm62 cm