Institute of Polymers, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5-10, 8093 Zürich, Switzerland.
Chem Soc Rev. 2020 Aug 7;49(15):5140-5158. doi: 10.1039/d0cs00176g. Epub 2020 Jun 29.
Covalent long-range ordered (crystalline) sheets called 2D polymers have recently been synthesized by irradiating single crystals of suitably packed monomers. To have such an action proceed successfully, billions of bond formation processes have to be mastered exclusively in two dimensions within 3D crystals. This raises questions as to how to elucidate the mechanism of these unusual polymerizations as well as their entire strain management. The article will show that single crystal X-ray diffraction based on both Bragg and diffuse scattering are powerful techniques to achieve such goal. The very heart of both techniques will be explained and it will be shown what can be safely concluded with their help and what not. Consequently, the reader will understand why some crystals break during polymerization, while others stay intact. This understanding will then be molded into a few guidelines that should help pave the way for future developments of 2D polymers by those interested in joining the effort with this fascinating and emerging class of 2D materials.
最近，通过辐照适当堆积的单体的单晶，已经合成了称为 2D 聚合物的共价长程有序（结晶）片。为了使这种反应成功进行，必须在 3D 晶体中仅在二维空间内成功掌握数十亿个键形成过程。这就提出了如何阐明这些不寻常聚合反应及其整个应变管理的机制的问题。本文将表明，基于布拉格和漫散射的单晶 X 射线衍射是实现这一目标的强大技术。这两种技术的核心将得到解释，并将展示借助它们可以安全得出哪些结论，以及不能得出哪些结论。因此，读者将了解为什么有些晶体在聚合过程中会破裂，而有些晶体则保持完整。然后，将这些理解转化为一些准则，这些准则应该有助于为那些有兴趣加入这一迷人且新兴的二维材料领域的人铺平未来 2D 聚合物发展的道路。
