Understanding the Electronic Structure of 4d Metal Complexes: From Molecular Spinors to L-Edge Spectra of a di-Ru Catalyst
Understanding the Electronic Structure of 4d Metal Complexes: From Molecular Spinors to L-Edge Spectra of a di-Ru Catalyst
复制标题
DOI：
10.1021/ja207409q
复制
发表时间：
2011-10-05
影响因子：
15
通讯作者：
Pushkar, Yulia
中科院分区：
文献类型：
--
作者：
Alperovich, Igor;Smolentsev, Grigory;Pushkar, Yulia
L-2，L-3边X射线吸收光谱（XAS）已被证明具有分析二钌配合物电子结构的独特能力，如蓝色二聚体cis，cis-[（Ru 2 O）-O-III（H2O）（2）（bpy）（4）]（4+）水氧化催化剂。蓝色二聚体和单体[Ru（NH3）（6）]（3+）模型配合物的光谱显示了Ru L-2，L-3吸收边的明显不同的分裂，这反映了与桥连配体的杂化和自旋轨道耦合效应引起的Ru 4d轨道相对能量的变化。为了帮助解释光谱数据，我们开发了一种新的方法，它计算的L-2，L-3边XAS光谱作为偶极跃迁之间的分子旋量的4d过渡金属配合物。这允许仔细列入的自旋-轨道耦合效应和杂交的Ru 4d和配体轨道。理论计算得到的Ru的L-2、L-3边谱与实验结果符合较好。关键的是，现有的单电子方法（FEFF，FDMNES）广泛用于模拟XAS不能再现实验Ru L-边光谱的[Ru（NH3）（6）]（3+）模型配合物，也没有蓝色二聚体，而电荷转移多重（CTM）计算是不适用的，由于复杂性和低对称性的蓝色二聚体水氧化催化剂。我们证明，L-边光谱是信息分析的桥接金属配合物。所开发的计算方法增强了L-边光谱作为分析配合物，材料，催化剂和活性中间体与4d过渡金属的电子结构的工具。
L-2,L-3-edge X-ray absorption spectroscopy (XAS) has demonstrated unique capabilities for the analysis of the electronic structure of di-Ru complexes such as the blue dimer cis,cis-[(Ru2O)-O-III(H2O)(2)(bpy)(4)](4+) water oxidation catalyst. Spectra of the blue dimer and the monomeric [Ru(NH3)(6)](3+) model complex show considerably different splitting of the Ru L-2,L-3 absorption edge, which reflects changes in the relative energies of the Ru 4d orbitals caused by hybridization with a bridging ligand and spin-orbit coupling effects. To aid the interpretation of spectroscopic data, we developed a new approach, which computes L-2,L-3-edges XAS spectra as dipole transitions between molecular spinors of 4d transition metal complexes. This allows for careful inclusion of the spin-orbit coupling effects and the hybridization of the Ru 4d and ligand orbitals. The obtained theoretical Ru L-2,L-3-edge spectra are in close agreement with experiment. Critically, existing single-electron methods (FEFF, FDMNES) broadly used to simulate XAS could not reproduce the experimental Ru L-edge spectra for the [Ru(NH3)(6)](3+) model complex nor for the blue dimer, while charge transfer multiplet (CTM) calculations were not applicable due to the complexity and low symmetry of the blue dimer water oxidation catalyst. We demonstrated that L-edge spectroscopy is informative for analysis of bridging metal complexes. The developed computational approach enhances L-edge spectroscopy as a tool for analysis of the electronic structures of complexes, materials, catalysts, and reactive intermediates with 4d transition metals.