通过侧链相互作用调整晶体性和叠加二维共价有机框架
Chloe E Pelkowski1, Anusree Natraj1, Christos D Malliakas1
1Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States.
Journal of the American Chemical Society
|September 29, 2023
概括
研究人员探索了吊链长度如何影响二维共价有机框架 (2D COF) 的堆叠和结晶性. 长链意外导致更多的晶体材料, 提供超分子组合的洞察力,
科学领域:
- 材料科学
- 超分子化学
- 聚合物化学
背景情况:
- 二维共价有机框架 (2D COF) 是层叠的聚合物,其可调节性质受到层间堆叠的影响.
- 控制二维COF的堆叠安排对于它们的新兴性质至关重要,但原则仍然不太清楚.
- 许多二维COF表现出无序的堆叠,限制了它们的潜在应用.
研究的目的:
- 调查悬挂-氧链长度对二维胺结合COF的堆叠几何和结晶性的影响.
- 通过侧链长度的系统变化,阐明二维COF中的超分子组合的基本原则.
- 确定生产高晶度二维COF的战略.
主要方法:
- 一系列2D imine-linked COFs与从C1到C11的基链的合成
- 使用粉末X射线衍射 (PXRD) 和扫描电子显微镜 (SEM) 来评估结晶性和形态.
- 分子动力学 (MD) 模拟和现场质子NMR光谱学,以了解自我组装机制和反应平衡.
主要成果:
- 一个C1链的COF显示了阴影堆叠,而较长的链 (C2-C11) 显示了单向滑动堆叠,偏移到C6.
- 与直觉相反,较短的链 (C1-C4) 产生了少量的弱结晶材料,而较长的链 (C5-C11) 则产生了高结晶COF的产量.
- MD模拟表明有利的长链相互作用促进了板的自我组装,NMR对反应平衡和结晶性的洞察力得到了证实.
结论:
- 吊链的长度对二维COF的堆叠几何和结晶度都有很大的影响.
- 可以使用更长的基链来增强自组装并促进高度结晶的2DCOF的形成.
- 这项研究为设计先进的晶体COF材料提供了对超分子组装原理的基本见解.
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