Experimental and theoretical correlations between vanadium K-edge X-ray absorption and Kβ emission spectra.
Experimental and theoretical correlations between vanadium K-edge X-ray absorption and Kβ emission spectra.
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DOI：
10.1007/s00775-016-1358-7
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发表时间：
2016-09
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影响因子：
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通讯作者：
DeBeer S
中科院分区：
文献类型：
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作者：
Rees JA;Wandzilak A;Maganas D;Wurster NI;Hugenbruch S;Kowalska JK;Pollock CJ;Lima FA;Finkelstein KD;DeBeer S
用K边X射线吸收谱（XAS）和K边X射线发射谱（XES）研究了一系列钒化合物。数据集内的定性趋势，以及XAS和XES数据之间的比较，说明了这两种方法的信息内容。化学洞察力的互补性突出了这种双重技术方法在表征钒位点的结构和电子性质方面的成功。特别是，与XAS或扩展X射线吸收精细结构（EXAFS）相反，我们证明，价到核心XES能够区分具有相同身份但不同键合特性的配位原子。最后，密度泛函理论（DFT）和含时DFT计算使数据的更详细，定量的解释。我们还建立了校正因子的计算协议，通过校准实验。这些硬X射线方法可以探测任何氧化态或自旋态的钒离子，并且可以很容易地应用于从固相催化剂到冷冻溶液中的生物样品的样品环境。因此，结合XAS和XES方法，再加上DFT计算，为生物无机化学中钒原子的研究提供了一个强大的工具。本文的在线版本（doi：10.1007/s 00775 -016-1358-7）包含补充材料，可供授权用户使用。
A series of vanadium compounds was studied by K-edge X-ray absorption (XAS) and K X-ray emission spectroscopies (XES). Qualitative trends within the datasets, as well as comparisons between the XAS and XES data, illustrate the information content of both methods. The complementary nature of the chemical insight highlights the success of this dual-technique approach in characterizing both the structural and electronic properties of vanadium sites. In particular, and in contrast to XAS or extended X-ray absorption fine structure (EXAFS), we demonstrate that valence-to-core XES is capable of differentiating between ligating atoms with the same identity but different bonding character. Finally, density functional theory (DFT) and time-dependent DFT calculations enable a more detailed, quantitative interpretation of the data. We also establish correction factors for the computational protocols through calibration to experiment. These hard X-ray methods can probe vanadium ions in any oxidation or spin state, and can readily be applied to sample environments ranging from solid-phase catalysts to biological samples in frozen solution. Thus, the combined XAS and XES approach, coupled with DFT calculations, provides a robust tool for the study of vanadium atoms in bioinorganic chemistry. The online version of this article (doi:10.1007/s00775-016-1358-7) contains supplementary material, which is available to authorized users.