X-ray Emission Spectroscopy To Study Ligand Valence Orbitals in Mn Coordination Complexes
X-ray Emission Spectroscopy To Study Ligand Valence Orbitals in Mn Coordination Complexes
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DOI：
10.1021/ja808526m
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发表时间：
2009-09-16
影响因子：
15
通讯作者：
Glatzel, Pieter
中科院分区：
文献类型：
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作者：
Smolentsev, Grigory;Soldatov, Alexander V.;Glatzel, Pieter
讨论了在配位和生物无机化学中测定化学键性质和金属配体鉴定的光谱方法。它是基于对x射线发射光谱中的卫星谱线的分析，这些谱线是由价轨道和金属离子1s能级（价核x）之间的跃迁引起的。光谱与基于密度泛函理论（DFT）的计算相结合，提供了与其他光谱技术互补的信息，特别是x射线吸收（XANES和EXAFS）。光谱形状对配体的质子化很敏感，可以区分原子序数稍有不同的配体（例如，C、N、O中心点中心点中心点）。从分子轨道的角度对一系列Mn模型体系[Mn(H2O)(6)]（2+）、[Mn(H2O)(5)OH]（+）和[Mn(H2O)(5)NH3]（2+）的主要光谱特征进行了理论讨论。将该方法应用于Mn -2 +离子在水中的溶剂化和3种Mn配位配合物[LMn(acac)N-3]BPh4、[LMn(B2O3Ph2)(ClO4)]和[LMn(acac)N]BPh4，其中L代表1,4,7-三甲基-1,4,7-三氮杂环壬烷，acac代表2,4-戊二酸阴离子，B2O3Ph2代表1,3-二苯基-1,3-二硼-2-甲丙烷-1,3-二氮杂二醇离子。
We discuss a spectroscopic method to determine the character of chemical bonding and for the identification of metal ligands in coordination and bioinorganic chemistry. It is based on the analysis of satellite lines in X-ray emission spectra that arise from transitions between valence orbitals and the metal ion 1s level (valence-to-core XES). The spectra, in connection with calculations based on density functional theory (DFT), provide information that is complementary to other spectroscopic techniques, in particular X-ray absorption (XANES and EXAFS). The spectral shape is sensitive to protonation of ligands and allows ligands, which differ only slightly in atomic number (e.g., C, N, O center dot center dot center dot), to be distinguished. A theoretical discussion of the main spectral features is presented in terms of molecular orbitals for a series of Mn model systems: [Mn(H2O)(6)](2+), [Mn(H2O)(5)OH](+), and [Mn(H2O)(5)NH3](2+). An application of the method, with comparison between theory and experiment, is presented for the solvated Mn 2+ ion in water and three Mn coordination complexes, namely [LMn(acac)N-3]BPh4, [LMn(B2O3Ph2)(ClO4)], and [LMn(acac)N]BPh4, where L represents 1,4,7-trimethyl-1,4,7-triazacyclononane, acac stands for the 2,4-pentanedionate anion, and B2O3Ph2 represents the 1,3-diphenyl-1,3-dibora-2-oxapropane-1,3-diolato dianion.