Chemically Stable Multilayered Covalent Organic Nanosheets from Covalent Organic Frameworks via Mechanical Delamination
Chemically Stable Multilayered Covalent Organic Nanosheets from Covalent Organic Frameworks via Mechanical Delamination
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DOI：
10.1021/ja408121p
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发表时间：
2013-11-27
影响因子：
15
通讯作者：
Banerjee, Rahul
中科院分区：
文献类型：
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作者：
Chandra, Suman;Kandambeth, Sharath;Banerjee, Rahul
采用溶剂热法合成了TpPa-NO2、TpPa-F-4、TpBD-（NO2）（2）、TpBD-Me-2和TpBD-（OMe）（2）五种热稳定性和化学稳定性较好的共价有机骨架（COFs）。为了完成该系列，以前报道的TpPa-1，TpPa-2，和TpBD也被合成，并通过粉末X射线衍射（PXRD），傅里叶变换红外（FT-IR）光谱，C-13固态NMR光谱，和热重分析，总共，8个COFs进行了充分的表征。这些COF是结晶的，永久多孔的，并且在沸水、酸（9 N HCl）和碱（3 N NaOH）中稳定。的.合成的COF（所有八种）使用简单、安全和环境友好的机械研磨路线成功地分层以转化成共价有机纳米片（CON），并通过透射电子显微镜和原子力显微镜进行良好表征。进一步的PXRD和FT-IR分析证实，这些CON在整个分层过程中保持其结构完整性，并且在水性、酸性和碱性介质中也保持稳定，如母体COF。这些剥离的CON具有石墨烯样的层状形态（分层层），与合成它们的COF不同。
A series of five thermally and chemically stable functionalized covalent organic frameworks (COFs), namely, TpPa-NO2, TpPa-F-4, TpBD-(NO2)(2), TpBD-Me-2, and TpBD-(OMe)(2) were synthesized by employing the solvothermal aldehyde-amine Schiff base condensation reaction. In order to complete the series, previously reported TpPa-1, TpPa-2, and TpBD have also been synthesized, and altogether, eight COFs were fully characterized through powder X-ray diffraction (PXRD), Fourier transform IR (FT-IR) spectroscopy, C-13 solid-state NMR spectroscopy, and thermogravimetric analysis. These COFs are crystalline, permanently porous, and stable in boiling water, acid (9 N HCl), and base (3 N NaOH). The. synthesized COFs (all eight) were successfully delaminated using a simple, safe, and environmentally friendly mechanical grinding route to transform into covalent organic nanosheets (CONs) and were well characterized via transmission electron microscopy and atomic force microscopy. Further PXRD and FT-IR analyses confirm that these CONs retain their structural integrity throughout the delamination process and also remain stable in aqueous, acidic, and basic media like the parent COFs. These exfoliated CONs have graphene-like layered morphology (delaminated layers), unlike the COFs from which they were synthesized.