Theoretical Study of the Luminescent States and Electronic Spectra of UO2Cl2 in an Argon Matrix.
Theoretical Study of the Luminescent States and Electronic Spectra of UO2Cl2 in an Argon Matrix.
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DOI：
10.1021/ct200419x
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发表时间：
2011-09
影响因子：
5.5
通讯作者：
Jing Su;Yi-Lei Wang;Fan Wei;W. Schwarz;Jun Li
中科院分区：
文献类型：
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作者：
Jing Su;Yi-Lei Wang;Fan Wei;W. Schwarz;Jun Li
在从头算完全活性空间二级微扰理论（CASPT 2）和耦合团簇单、双和微扰三重态[CCSD（T）]水平上，采用原子价3 π极化基组，研究了自由UO 2Cl 2及其Ar配位配合物在27 000 cm（-1）以下的电子吸收和发射光谱.通过研究氩配合物ArnUO_2Cl_2的激发态，探讨了12 K实验中氩基体对电子光谱的影响。计算得到的两个最稳定的n = 2，3的配合物可以解释实验中观察到的两个基质位对应的双组分发光衰减。在这些铀酰配合物中，Ar配位对发光态的（3）Φ（Ω = 2g）特征和电子光谱形状几乎没有影响。计算产生的实验激发光谱的相干分配，提高了以前的分配。根据CASPT 2和CCSD（T）计算的UO_2Cl_2的光谱参数，模拟得到的发光光谱曲线与实验结果吻合较好。
The electronic absorption and emission spectra of free UO2Cl2 and its Ar-coordinated complexes below 27 000 cm(-1) are investigated at the levels of ab initio complete active space second-order perturbation theory (CASPT2) and coupled-cluster singles and doubles and perturbative triples [CCSD(T)] using valence 3ζ-polarized basis sets. The influence of the argon matrix in the 12K experiment on the electronic spectra is explored by investigating the excited states of argon complexes ArnUO2Cl2. The calculated two most stable complexes with n = 2, 3 can explain the observed two matrix sites corresponding to the experimental two-component luminescence decay. In these uranyl complexes, Ar-coordination is found to have little influence on the (3)Φ (Ω = 2g) character of the luminescent state and on the electronic spectral shape. The calculations yield a coherent assignment of the experimental excitation spectra that improves on previous assignments. The simulated luminescence spectral curves based on the calculated spectral parameters of UO2Cl2 from both CASPT2 and CCSD(T) agree well with experiment.