以高精度的完全活化空间自洽场及二级微扰能量校正(CASFlE//CASSCF)电子结构计算为基础,利用Forster和Dexter2种模型,建立了能量转移速率的数值模拟方案,并将其用于2种典型的有机发光二极管发光分子—-Pt-4和FPt的光物理过程的计算,结果发现,蓝光态到红光态的能量转移和蓝光态到基态的辐射跃迁之间的竞争决定了发光颜色的浓度依赖性,阐明了2个配合物溶液体系发射白光的微观机制.通过比较2个配合物单体和双体不同电子态的结构和性质的差异,对发光颜色与溶液浓度依赖性的微观本质给出了新的理论.此外,本文建立的能量转移速率模拟方案,同时适用于其它激发态电子结构方法,因此具有普适性.
A comprehensive theoretical model, based on the quantitative energy transfer theory (Ftirster and Dexter theories) and accurate electronic structure calculations at the CASPT2//CASSCF level was introduced to account for the mechanism of photophysics and tunable emission for Pt-4 and FPt, which are two of promi- sing phosphors for organic light-emitting diodes (0LEDs). For a larger intermolecular distance, the energy tranfer rate is not competitive with the radiative transition, and the blue emission becomes the predominant channel. When the distance decreases to the typical value in the dimer, the energy transfer rate exceeds that of the blue emission and reproduces highly efficient red emission. At the intermediate distance, the blue and red emissions could reach a balance, which results in a mixing white emission.