Thermodynamics and Conformations in the Formation of Excited States and Their Interconversions for Twisted Donor-Substituted Tridurylboranes
作者:Mao Mao、Ming-Guang Ren、Qin-Hua Song
DOI:10.1002/chem.201201719
日期:2012.11.26
state conversion is opposite to the viscosity effect, and temperature effects derive from its resulting changes of polarity and viscosity. For example, the increase of the polarity of the solvent results in excited‐state conversions from the LE state to the ICT state, and/or from the ICT to the TICT state, and an increased viscosity leads to the opposite conversions. On the basis of electrochemical
我们合成了一系列供体取代的三硬脂酸硼烷,它们包含不同类型和数量的生色团,包括1-py(PB1-3),3-咔唑(CBC1-3)或取代的对-咔唑-N-苯基(CBN3a–c)作为各种供体-受体(D–A)分子。通过UV / Vis吸收和荧光光谱以及循环伏安法(CV)研究了这些扭曲的D–A分子的光物理和电化学性质。溶剂极性,粘度和温度对荧光发射的影响揭示了三种激发态的存在,以及它们在三种激发态之间的平衡和相互转化。与电荷分离程度和构象变化的顺序有关,与之相比,三个激发态为局部激发(LE)状态,分子内电荷转移(ICT)状态更加平坦,ICT(TICT)状态更加扭曲基态。TICT状态正在经历构象变化,与ICT状态相比,能源壁垒更高。溶剂极性对状态转换的影响与粘度影响相反,而温度影响则源于其极性和粘度的变化。例如,溶剂极性的增加导致从LE状态到ICT状态和/或从ICT到TICT状态的激发态转化,而粘度增加导