Two-dimensional sp2 carbon-conjugated covalent organic frameworks
Two-dimensional sp2 carbon-conjugated covalent organic frameworks
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DOI：
10.1126/science.aan0202
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发表时间：
2017-08-18
期刊：
影响因子：
56.9
通讯作者：
Jiang, Donglin
中科院分区：
文献类型：
--
作者：
Jin, Enquan;Asada, Mizue;Jiang, Donglin
通过四(4-甲酰基苯基)芘和1，4-苯二乙腈的C=C缩合反应，我们合成了一种完全pi共轭的二维(2D)晶体共价有机骨架(sp(2)c-COF)。C=C键在拓扑上以规则的间隔连接到具有沿x和y方向延伸的pi共轭的2D晶格中，并且形成了遮盖层骨架，而不是传统上获得的无序结构。SP(2)c-COF是一种半导体，具有1.9电子伏特的离散带隙，可以通过化学氧化将电导率提高12个数量级。生成的自由基被限制在芘结上，从而能够形成具有高自旋密度的顺磁性碳结构。SP(2)碳骨架诱导铁磁相变发展自旋-自旋相干，并在材料上单向排列自旋。
We synthesized a two-dimensional (2D) crystalline covalent organic framework (sp(2)c-COF) that was designed to be fully pi-conjugated and constructed from all sp(2) carbons by C=C condensation reactions of tetrakis(4-formylphenyl)pyrene and 1,4-phenylenediacetonitrile. The C=C linkages topologically connect pyrene knots at regular intervals into a 2D lattice with pi conjugations extended along both x and y directions and develop an eclipsed layer framework rather than the more conventionally obtained disordered structures. The sp(2)c-COF is a semiconductor with a discrete band gap of 1.9 electron volts and can be chemically oxidized to enhance conductivity by 12 orders of magnitude. The generated radicals are confined on the pyrene knots, enabling the formation of a paramagnetic carbon structure with high spin density. The sp(2) carbon framework induces ferromagnetic phase transition to develop spin-spin coherence and align spins unidirectionally across the material.