The electronic structure of Mn in oxides, coordination complexes, and the oxygen-evolving complex of photosystem II studied by resonant inelastic X-ray scattering
The electronic structure of Mn in oxides, coordination complexes, and the oxygen-evolving complex of photosystem II studied by resonant inelastic X-ray scattering
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DOI：
10.1021/ja038579z
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发表时间：
2004-08-18
影响因子：
15
通讯作者：
Yachandra, VK
中科院分区：
文献类型：
--
作者：
Glatzel, P;Bergmann, U;Yachandra, VK
利用共振非弹性X射线散射（RIXS）技术收集Mn K前沿谱，研究氧化物、分子配位化合物以及光系统II（PS II）放氧复合物（OEC）的S-1和S-2态的电子结构. RIXS数据产生的二维图，可以解释沿着入射（吸收）能量或能量转移轴。第二能量维度将前边缘（主要是1 s到3d的过渡）与主K边缘分开，因此可以进行详细的分析。1 s2 p RIXS最终状态的电子配置沿着的能量转移轴是相同的，传统的L边吸收光谱，和RIXS光谱，因此敏感的Mn自旋状态。因此，这种新技术产生的电子结构的信息是无法在传统的K边吸收光谱。线分裂可以在配体场多重态模型内理解，即，(3d，3d）和（2 p，3d）两电子相互作用对于描述所有体系的光谱形状都是至关重要的。我们建议解释Mn氧化后的K前边缘吸收能量的移位的有效3d电子数（分数3d轨道人口）。PS II S和S2状态之间的Mn 1 s2 p（3/2）RIXS光谱中的光谱变化与氧化物和两种配位络合物（Mn-III（acac）（3）和Mn-IV（sal）（2）（bipy））的光谱变化相比是小的。我们得出结论，从S-1到S-2的步骤中的电子是从一个强离域轨道转移。
Resonant inelastic X-ray scattering (RIXS) was used to collect Mn K pre-edge spectra and to study the electronic structure in oxides, molecular coordination complexes, as well as the S-1 and S-2 states of the oxygen-evolving complex (OEC) of photosystem II (PS II). The RIXS data yield two-dimensional plots that can be interpreted along the incident (absorption) energy or the energy transfer axis. The second energy dimension separates the pre-edge (predominantly 1s to 3d transitions) from the main K-edge, and a detailed analysis is thus possible. The 1s2p RIXS final-state electron configuration along the energy transfer axis is identical to conventional L-edge absorption spectroscopy, and the RIXS spectra are therefore sensitive to the Mn spin state. This new technique thus yields information on the electronic structure that is not accessible in conventional K-edge absorption spectroscopy. The line splittings can be understood within a ligand field multiplet model, i.e., (3d,3d) and (2p,3d) two-electron interactions are crucial to describe the spectral shapes in all systems. We propose to explain the shift of the K pre-edge absorption energy upon Mn oxidation in terms of the effective number of 3d electrons (fractional 3d orbital population). The spectral changes in the Mn 1s2p(3/2) RIXS spectra between the PS II S, and S2 states are small compared to that of the oxides and two of the coordination complexes (Mn-III(acac)(3) and Mn-IV(sal)(2)(bipy)). We conclude that the electron in the step from S-1 to S-2 is transferred from a strongly delocalized orbital.