Density functional theory calculation was performed to analyze the critical factors determining whether molecule has a thermally activated delayed fluorescence (TADF) characteristic by comparing two similar molecules (1 and 2), which have a little difference in structure but opposite TADF performance. Some parameters relevant to TADF property were evaluated in this work. The results indicate that although the HOMO and LUMO distributions of 1 and 2 are similar and the radiative decay rate (k_r) of 1 is even greater than that of 2, 2 has the smaller singlet-triplet energy splitting (ΔE_ST) and larger spin-orbital coupling (SOC) strength than 1. Besides, 2 has a smaller energy gap between S₁/T₁ minimum energy crossing point (MECP) and S₁ than 1, indicating that it is easy for 2 to realize reverse intersystem crossing (RISC) from T₁ to S₁. Therefore, a comprehensive comparison between 1 and 2 suggests that the parameters including ΔE_ST, SOC and MECP between S₁ and T₁ are fairly important factors determining the TADF characteristic of 2.

通过比较两个相似的分子（1和2），其结构差异不大，但TADF性能相反，通过密度泛函理论计算来分析确定分子是否具有热激活延迟荧光（TADF）特性的关键因素。在这项工作中评估了与TADF属性相关的一些参数。结果表明，尽管所HOMO和LUMO分布1和2是类似与辐射衰变速率（ķ _ř的）1比的更大的2，2具有较小的单线态-三线态能量分裂（Δ Ë _ST），以及较大的自旋-轨道耦合（SOC）强度比1。此外，2具有S之间的更小的能隙₁ / T _1个的最小能量交叉点（MECP）和S ₁比1，这表明它是便于2实现反向系间窜越（RISC）在T ₁至S ₁。因此，对1和2的全面比较表明，S ₁和T ₁之间的包括ΔE _ST，SOC和MECP的参数是决定2的TADF特性的相当重要的因素。。