Information Optoelectronics Research Institute, Harbin Institute of Technology at Weihai, Weihai 264209, People's Republic of China.
J Comput Chem. 2012 Apr 15;33(10):1038-46. doi: 10.1002/jcc.22935. Epub 2012 Feb 21.
In the search for efficiently phosphorescent materials, this article presents a rational design and theoretical comparative study of some photophysical properties in the (fpmb)(x)Ir(bptz)(3-x) (x = 1-2), which involve the usage of two 2-pyridyl triazolate (bptz) chromophores and a strong-field ligand fpmb (fpmb = 1-(4-difluorobenzyl)-3-methylbenzimidazolium). The first principle theoretical analysis under the framework of the time-dependent density functional theory approach is implemented in this article to investigate the electronic structures, absorption and phosphorescence spectra. It is intriguing to note that 1 and 2 exhibit theirs blue phosphorescent emissions with maxima at 504 and 516 nm, respectively. Furthermore, to obtain the mechanism of low phosphorescence yield in 1 and estimate the radiative rate constant k(r) for 2, we approximately measure the radiative rate constant k(r), the spin-orbital coupling (SOC) value, ΔE (S - T), and the square of the SOC matrix element (<Ψ(S1·)H(SO·)Ψ(T1)>(2)) for 1 and 2. Finally, we tentatively come to conclusion that the switch of the cyclometalated ligand from the main to ancillary chelate seems to lower the splitting ΔE (S - T) in the current system.
在寻找高效磷光材料的过程中，本文提出了一种（fpmb）（x）Ir（bptz）（3-x）（x=1-2）的合理设计和理论比较研究，该研究涉及使用两个 2-吡啶三唑（bptz）发色团和强场配体 fpmb（fpmb=1-（4-二氟苄基）-3-甲基苯并咪唑鎓）。本文采用基于含时密度泛函理论方法的第一性原理理论分析来研究电子结构、吸收和磷光光谱。有趣的是，1 和 2 分别表现出最大发射波长为 504nm 和 516nm 的蓝色磷光发射。此外，为了获得 1 中磷光产率低的机制并估计 2 的辐射速率常数 k(r)，我们近似测量了辐射速率常数 k(r)、自旋轨道耦合（SOC）值、ΔE（S-T）和 SOC 矩阵元素的平方(<Ψ(S1·)H(SO·)Ψ(T1)>(2))，用于 1 和 2。最后，我们初步得出结论，在当前体系中，从主螯合到辅助螯合的金属环化配体的切换似乎降低了分裂ΔE（S-T）。
