Zhao Xueyuan, Zhang Xinning, Li Xin, Wu Lin, Ji Lei
Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an, 710072, China.
Key Laboratory of Flexible Electronics of Zhejiang Province, Ningbo Institute of Northwestern Polytechnical University, Ningbo, 315103, China.
Chemistry. 2024 Jun 20;30(35):e202401246. doi: 10.1002/chem.202401246. Epub 2024 May 22.
A thorough understanding of the internal conversion process between excited states is important for the designing of ideal multiple-emissive materials. However, it is hard to experimentally measure both the energy barriers and gaps between the excited states of a compound. For a long time, it is dubious if what was measured is the energy gap or barrier between two excited states. In this paper, we designed 1-(pyren-2'-yl)-9,12-di(p-tolyl)-o-carborane (2), which shows dual-emission in solution. Temperature-dependent fluorescence measurements show that the two emission bands in hexane are corresponding to two different excited states. The ratio of the emission bands is controlled by thermodynamics at higher temperatures and by kinetics at lower temperatures. Thus, the energy barrier and energy gaps between the two excited states of 2 can be experimentally estimated.
深入理解激发态之间的内转换过程对于设计理想的多发射材料至关重要。然而，要通过实验测量化合物激发态之间的能垒和能隙却很困难。长期以来，所测量的究竟是两个激发态之间的能隙还是能垒一直存在疑问。在本文中，我们设计了1-(芘-2'-基)-9,12-二(对甲苯基)-邻碳硼烷(2)，它在溶液中呈现双发射。变温荧光测量表明，己烷中的两个发射带对应于两个不同的激发态。在较高温度下，发射带的比例由热力学控制，而在较低温度下则由动力学控制。因此，可以通过实验估算2的两个激发态之间的能垒和能隙。
