Dutra José Diogo L, Lima Nathalia B D, Freire Ricardo O, Simas Alfredo M
Pople Computational Chemistry Laboratory, Departamento de Química, CCET, UFS, 49100-000, Aracaju, SE, Brazil.
Departamento de Química Fundamental, CCEN, UFPE, 50590-470, Recife, PE, Brazil.
Sci Rep. 2015 Sep 2;5:13695. doi: 10.1038/srep13695.
We advance the concept that the charge factors of the simple overlap model and the polarizabilities of Judd-Ofelt theory for the luminescence of europium complexes can be effectively and uniquely modeled by perturbation theory on the semiempirical electronic wave function of the complex. With only three adjustable constants, we introduce expressions that relate: (i) the charge factors to electronic densities, and (ii) the polarizabilities to superdelocalizabilities that we derived specifically for this purpose. The three constants are then adjusted iteratively until the calculated intensity parameters, corresponding to the (5)D0→(7)F2 and (5)D0→(7)F4 transitions, converge to the experimentally determined ones. This adjustment yields a single unique set of only three constants per complex and semiempirical model used. From these constants, we then define a binary outcome acceptance attribute for the adjustment, and show that when the adjustment is acceptable, the predicted geometry is, in average, closer to the experimental one. An important consequence is that the terms of the intensity parameters related to dynamic coupling and electric dipole mechanisms will be unique. Hence, the important energy transfer rates will also be unique, leading to a single predicted intensity parameter for the (5)D0→(7)F6 transition.
对于铕配合物的发光，简单重叠模型的电荷因子和贾德 - 奥费尔特理论的极化率可以通过对配合物的半经验电子波函数进行微扰理论有效地且唯一地建模。仅用三个可调常数，我们引入了相关表达式：（i）将电荷因子与电子密度联系起来，以及（ii）将极化率与我们专门为此目的推导的超离域化联系起来。然后迭代调整这三个常数，直到对应于((^5D_0→^7F_2))和((^5D_0→^7F_4))跃迁的计算强度参数收敛到实验测定的值。这种调整为每个使用的配合物和半经验模型产生了仅由三个常数组成的唯一一组值。从这些常数出发，我们接着为调整定义一个二元结果接受属性，并表明当调整可接受时，预测的几何结构平均而言更接近实验结构。一个重要的结果是，与动态耦合和电偶极机制相关的强度参数项将是唯一的。因此，重要的能量转移速率也将是唯一的，从而导致((^5D_0→^7F_6))跃迁的单一预测强度参数。
