碗形碳纳米带显示尺寸依赖性和C70的选择性封装
Xuefeng Lu1, Tullimilli Y Gopalakrishna1, Yi Han1
1Department of Chemistry , National University of Singapore , 3 Science Drive 3 , Singapore 117543.
Journal of the American Chemical Society
|March 26, 2019
概括
研究人员合成了具有独特电子和超分子特性的新型碗形碳纳米带 (CNB). 较小的CNB选择性地封装C70富勒因,展示了先进分子识别应用的潜力.
科学领域:
- 纳米碳化学
- 材料科学
- 超分子化学
背景情况:
- 精确结构的碳纳米带 (CNB) 的合成是一个重大挑战.
- 了解CNB结构,电子特性和超分子行为之间的关系至关重要.
研究的目的:
- 合成和描述两个完全结合的,碗形的碳纳米带 (CNB1和CNB2).
- 研究它们独特的几何,电子,氧化还原和超分子性质.
- 探索它们的分子封装潜力.
主要方法:
- 合成碗形的CNB.
- 进行X射线晶体分析和密度函数理论 (DFT) 计算以确定结构.
- 可变温度核磁共振 (NMR) 光谱用于反向屏障研究.
- 电化学方法用于减氧行为分析.
- 用于芳香度评估的光谱技术和计算方法 (ACID,NICS,2D-ISOS).
- 富勒封装实验
主要成果:
- 成功合成和表征两个碗形CNBs (CNB1/CNB2) 与化环和交替的pyrenyl/phenantryl单元.
- 通过X射线结晶学和DFT证实了碗形的几何形状.
- CNB1比CNB2表现出更深的碗和更高的反转障碍.
- 这两种CNB都显示出小的能量缺口,两极性氧化还原行为和可访问的基离子.
- 滴滴和四滴滴表现出开单基性质和可调节的芳香性 (芳香/反芳香).
- CNB1选择性地封装了具有高关联常数的C70烯,而CNB2则没有封装.
结论:
- 这项研究提出了具有可调节电子和几何性能的新型碗形CNB.
- 这些发现突出了尺寸和几何对碗对碗逆转和超分子相互作用的影响.
- CNB1的选择性富勒烯封装证明了其在宿主-客体化学和分子识别方面的潜力.
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