Yoshida Takefumi, Takaishi Shinya, Kumagai Shohei, Iguchi Hiroaki, Mian Mohammad Rasel, Yamashita Masahiro
Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aza-Aoba, Aramaki, Sendai 980-8578, Japan.
Dalton Trans. 2019 Aug 6;48(31):11628-11631. doi: 10.1039/c9dt01684h.
We performed X-ray absorption fine structure (XAFS) measurements on three representative bromo-bridged palladium compounds. In the X-ray absorption near-edge structure (XANES) spectra, the averaged-valence (AV) compound, [Pd3+(dabdOH)2Br]Br2 (1: dabdOH = (2S,3S)-2,3-diaminobutane-1,4-diol), and the mixed-valence (MV) compound, [Pd2+(en)2]Pd4+(en)2Br24 (2), showed significant differences in their spectra. In Pd(en)2Br2·H2O (3: en = ethylenediamine, Suc-C5 = dipentylsulfosuccinate), which exhibits an MV-AV phase transition, on the other hand, the spectroscopic difference between below and above the phase transition temperature was hardly observed due to the subtle difference in the oxidation states. In the extended X-ray absorption fine structure (EXAFS) spectra, a clear difference in the Pd-Br correlation region was observed upon the phase transition.
我们对三种具有代表性的溴桥联钯化合物进行了X射线吸收精细结构（XAFS）测量。在X射线吸收近边结构（XANES）光谱中，平均价态（AV）化合物[Pd³⁺(dabdOH)₂Br]Br₂（1：dabdOH = (2S,3S)-2,3-二氨基丁烷-1,4-二醇）和混合价态（MV）化合物[Pd²⁺(en)₂]Pd⁴⁺(en)₂Br₂₄（2）的光谱显示出显著差异。另一方面，在表现出MV-AV相变的Pd(en)₂Br₂·H₂O（3：en = 乙二胺，Suc-C₅ = 二戊基磺基琥珀酸盐）中，由于氧化态的细微差异，在相变温度上下几乎观察不到光谱差异。在扩展X射线吸收精细结构（EXAFS）光谱中，在相变时观察到Pd-Br相关区域存在明显差异。
