Van Kuiken Benjamin E, Hahn Anselm W, Maganas Dimitrios, DeBeer Serena
Max Planck Institute for Chemical Energy Conversion , Stiftstr. 34-36, D-45470 Mülheim an der Ruhr, Germany.
Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States.
Inorg Chem. 2016 Nov 7;55(21):11497-11501. doi: 10.1021/acs.inorgchem.6b02053. Epub 2016 Oct 12.
Spectroscopic probes of the electronic structure of transition metal-containing materials are invaluable to the design of new molecular catalysts and magnetic systems. Herein, we show that 2p3d resonant inelastic X-ray scattering (RIXS) can be used to observe both spin-allowed and (in the V case) spin-forbidden d-d excitation energies in molecular vanadium complexes. The spin-allowed d-d excitation energies determined by 2p3d RIXS are in good agreement with available optical data. In V(acac), a previously undetected spin-forbidden singlet state has been observed. The presence of this feature provides a ligand-field independent signature of V. It is also shown that d-d excitations may be obtained for porphyrin complexes. This is generally prohibitive using optical approaches due to intense porphyrin π-to-π* transitions. In addition, the intensities of charge-transfer features in 2p3d RIXS spectroscopy are shown to be a clear indication of metal-ligand covalency. The utility of 2p3d RIXS for future studies of complex inorganic systems is highlighted.
含过渡金属材料电子结构的光谱探针对于新型分子催化剂和磁性系统的设计具有重要价值。在此，我们表明2p3d共振非弹性X射线散射（RIXS）可用于观测分子钒配合物中自旋允许的以及（在钒的情况下）自旋禁阻的d-d激发能。通过2p3d RIXS测定的自旋允许的d-d激发能与现有光学数据高度吻合。在V(acac)中，观测到了一个先前未被检测到的自旋禁阻单重态。这一特征的存在提供了钒的一个与配体场无关的特征。还表明卟啉配合物也可获得d-d激发。由于卟啉强烈的π到π*跃迁，使用光学方法通常难以实现这一点。此外，2p3d RIXS光谱中电荷转移特征的强度表明了金属-配体的共价性。强调了2p3d RIXS在未来复杂无机系统研究中的实用性。
