New Electronic Structure of Quasi-One-Dimensional Halogen-Bridged Ni(III) Complexes with Strong Electron Correlations

具有强电子相关性的准一维卤桥Ni(III)配合物的新电子结构

基本信息

批准号：
09440240
负责人：
YAMASHITA Masahiro
金额：
$ 3.58万
依托单位：
TOKYO METOROPOLITAN UNIVERSITY (1999)Nagoya University (1997-1998)
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

项目摘要

Quasi-one-dimensional halogen-bridged mixed-valence metal compounds have attracted much attention because they show very interesting physical properties such as intense and diachronic intervalence charge transfer bandsm luminescence with large Stokes shifts, overton progression of resonance Raman spectra, large third order non-linear optical properties, solitons, polarons, etc. Among these compounds, the Pt and Pd compounds take the M (II)-M (IV) mixed valence states or CDW states, where the bridging halogens are distorted from the midpoints between neighboring two metal ions. On the other hand, the Ni compounds take the Ni(III) states or SDW states, where the bridging halogens are located at the midpoints between two metal ions. The Ni compounds have the similar electronic structures to those starting materials of copperoxide supercondutors. Then, the doping to the compounds are very interesting. According such strategy, we have synthesized Ni-Pd mixed-metal complexes by electrochemic … More al methods. In order to investigate their electronic structures, we have measured IR, Raman spectra, XPS, Auger spectra and ESR spectra.The XPS and Auger spectra revealed that the oxidation states of the Ni ions is +3, but the Pd(II)-Pd(IV) mixed-valence states approach the Pd(III) states with increase of Ni components. In the IR spectra, the doublet of υ(N-H) in Pd(II)-Pd(IV) is gradually changing to the singlet, indicating that the Pd(II)-Pd(IV) state approach the Pd(III) states. In the Raman spectra, the intensity and the number of overtone of υ(Pd(IV)-Br) decrease with increase of the Ni components as observed in IR spectra. The integrated spin susceptibilities at room temperature are enhanced compared with those pure mixture of Pd(II)-Pd(IV) and Ni(III), indicating that the Pd(II)-Pd(IV) states are changed to the Pd(III) sates.As mentioned above, the Pd(II)-Pd(IV) states are influenced and changed to the Pd(III) states with increase of the Ni(III) components. This is due to the stronger electron correlation of the Ni ions. Less

准一维卤桥混价金属化合物因其表现出非常有趣的物理性质而备受关注，例如具有大斯托克斯位移的强且历时区间电荷转移带发光、共振拉曼光谱的奥弗顿级数、大的三阶非-线性光学性质、孤子、极化子等。其中，Pt和Pd化合物采取M(II)-M(IV)混合价态或CDW态，其中桥接另一方面，Ni 化合物呈现 Ni(III) 态或 SDW 态，其中桥接卤素位于两个金属离子之间的中点。与氧化铜超导体的起始材料相似的电子结构然后，根据这种策略，我们通过电化学合成了 Ni-Pd 混合金属配合物。为了研究它们的电子结构，我们测量了红外光谱、拉曼光谱、XPS、俄歇光谱和ESR光谱。XPS和俄歇光谱显示Ni离子的氧化态为+3，但Pd(II)离子的氧化态为+3。随着Ni组分的增加，-Pd(IV)混合价态接近Pd(III)态。在红外光谱中，υ(N-H)的双峰出现。 Pd(II)-Pd(IV)逐渐向单线态转变，表明Pd(II)-Pd(IV)态在拉曼光谱中的泛音强度和数量接近Pd(III)态。 IR 光谱中观察到 υ(Pd(IV)-Br) 随着 Ni 组分的增加而降低，与 Pd(II)-Pd(IV) 和 Pd(IV) 的纯混合物相比，室温下的积分自旋敏感性增强。 Ni(III)，表明Pd(II)-Pd(IV)态转变为Pd(III)态。如上所述，Pd(II)-Pd(IV)态受到影响而转变为Pd (III)态随着Ni(III)组分的增加而增加，这是由于Ni离子的电子关联性更强。