OPTICAL AND MAGNETIC-PROPERTIES OF THE HALOGEN-BRIDGED METAL-COMPLEXES MODIFIED BY HYDROGEN BONDINGS - (M(1R,2R-CYCLOHEXANEDIAMINE)2BR)BR(M=PT, PD, AND NI)
OPTICAL AND MAGNETIC-PROPERTIES OF THE HALOGEN-BRIDGED METAL-COMPLEXES MODIFIED BY HYDROGEN BONDINGS - (M(1R,2R-CYCLOHEXANEDIAMINE)2BR)BR(M=PT, PD, AND NI)
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DOI：
10.1103/physrevb.42.10381
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发表时间：
1990-12-01
影响因子：
3.7
通讯作者：
YAMASHITA, M
中科院分区：
文献类型：
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作者：
OKAMOTO, H;TORIUMI, K;YAMASHITA, M
对新合成的卤素桥接一维（1D）金属配合物{M (chxn) 2br} Br 2 （M= Pt, Pd, Ni; chxn= 1R， 2r -环己二胺）单晶进行了极化反射和ESR测量，该配合物在配体（chxn）和反阴离子（Br−）之间具有紧密的氢键，并构建了二维（2D）氢键网络。偏振反射光谱和随温度变化的ESR信号表明，M= Ni的电子态与M= Pt（或Pd）的电子态有本质的不同。从这些结果的分析可以得出结论，M= Ni的配合物处于一价态，其中莫特绝缘体形成（-Ni 3+- br−-）规则链，而M= Pt和Pd的配合物则处于混合价态（- m2 +- br−- - m4 +- br−-）。Pd配合物的热激发顺磁自旋可以用二维氢键网络影响下的孤子扭结模型来解释。
Polarized reflection and ESR measurements have been carried out on single crystals of newly synthesized halogen-bridged one-dimensional (1D) metal complexes {M (chxn) 2 Br} Br 2 (M= Pt, Pd, Ni; chxn= 1R, 2R-cyclohexanediamine), which have tight hydrogen bonds between ligands (chxn) and counter anions (Br−) and construct a two-dimensional (2D) hydrogen-bond network. Both the polarized reflection spectra and the temperature-dependent ESR signals indicate that the electronic state of M= Ni is essentially different from that of M= Pt (or Pd). From the analysis of these results, it can be concluded that the complex for M= Ni is in a monovalent state, where a Mott insulator is formed in a (-Ni 3+-Br−-) regular chain, in contrast to the mixed-valent state (-M 2+-Br−-M 4+-Br−-) for M= Pt and Pd. Thermally excited paramagnetic spins observed for the Pd complex can be explained by the soliton-kink model under the influence of the 2D hydrogen-bond network.