Abstract:
We herein report the facile synthesis of two helical carbon nanorings with small ring sizes, cyclo[6]paraphenylene-1,5-naphthylene ([6]CPPNap1,5), and cyclo[6]paraphenylene-1,5-anthrylene ([6]CPPAn1,5). The structures were determined by NMR and HR-MS. X-ray single-crystal data of [6]CPPNap1,5 was also achieved. The strain energy and racemization processes were investigated by DFT calculations. The reduced ring sizes result in increased ring strain and elevated energy barriers. The photophysical properties were studied by UV-Vis absorption, fluorescence emission, and time-resolved fluorescence decay.
摘要:
我们在此报告了两个具有小环尺寸的螺旋碳纳米环的容易合成,环[6]对亚苯基-1,5-亚萘基([6]CPPNap1,5),和环[6]对亚苯基-1,5-蒽基([6]CPPAn1,5)。通过NMR和HR-MS确定结构。还获得了[6]CPPNap1,5的X射线单晶数据。通过DFT计算研究了应变能和外消旋过程。减小的环尺寸导致增加的环应变和升高的能量势垒。通过紫外-可见吸收研究了其光物理性质,荧光发射,和时间分辨荧光衰减。