Conjugated Crystals of Halogen-Bridged One-Dimensional Metal Complexes by Electrochemical Technique

电化学技术制备卤桥一维金属配合物的共轭晶体

• 批准号: 05453047
• 负责人: TORIUMI Koshiro
• 金额: $ 4.29万
• 依托单位: Himeji Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05453047/
• 关键词: halogen-bridge; crystal structure analysis; mixed valence; electrochemical oxidation; platinum dimer; phase transition; valence fluctuation; electron-phonon coupling; 混合原子価錯体; 格子定数の温度依存性; 一次元化合物; 混合原子価; 金属錯体; ハロゲン架橋; 電解酸化; 結晶構造解析

Halogen-bridged one-dimensional compounds having characteristic electron-phonon coupling seems to become high temperature superconductors, if electron rich or deficient columnar units could be coexists with the halogen-bridged linear chain in a crystal. In this project, we tried to prepare the new type of one-dimensional halogen-bridged Ni complexes by electrochemical technique. In addition, the phase transition of the iodo bridged Pt dimer complex with linear chain structure has been studied by the temperature dependent X-ray structure analysis.Two crystal forms (alpha and beta) of a novel halogen bridged one-dimensional Ni^<III>-Br-Ni^<III> compound, {[Ni(en)_2Br](ClO_4)_2}_*(en=C_2H_8N_2), have been prepared by electrochemical oxidation. X-ray crystal structure analysis of the alphaform revealed that a bridging Br ion is located on the midpoint between two Ni atoms and the Ni-Br distance of 2.640(1) * is significantly elongated by introducing a bulky ClO_4^- ion as a c anion. An ave … More rage Ni-Br distance of 2.693(2) * for the beta form can be estimated from the lattice parameter along the chain. Magnetic susceptibility data for bath forms show strong antiferromagnetic coupling (J=-1700K) between electronic spins (S=1/2) localized on the Ni^<III> on the linear chain.The halogen-bridged mixed-valence compound with MMX type linear chain structure, Pt_2(dta)_4I (dta=CH_3CS_2^-), exhibits metallic conduction between 300 and 340 K,which is the first observation in halogen-bridged one-dimensional metal complexes. The lattice parameters of Pt_2(dta)_4I have been measured by single crystal diffraction method in the temperature range of-160-190ﾟC,showing the anomalous hysteresis along with the first order (ca.90ﾟC)and the second order (ca.0ﾟC)phase transitions. Crystal structure analyzes have been made at several temperatures in the range of-89-130ﾟC by using an imaging plate detector installed to the Enraf- cad4 diffractometer. The crystal structure of high temperature phase with space group A2/m show the positional disorder of ligating S atoms of the dta ligands, which should be owing to the twisting motion of the Pt_2(dta)_4I unit, though the low-temperature phase of C2/c has no positional disorder. It appeared from the analysis of positional disorder in the intermediate phase that there is a molecular conformation which enhances the stretching amplitude of a Pt-Pt bond. The observed twisting thermal motion of the Pt_2(dta)_4 unit should be essential in a viewpoint of the electron-phonon coupling in the one-dimensional mixed-valence system which induce the electron transfer between platinum dimer units. Less

具有特征性电子-声子耦合的卤素桥一维化合物，如果富电子或缺电子的柱状单元能与卤素桥线性链共存，则有望成为高温超导体。本课题尝试用电化学方法制备新型一维卤素桥联镍配合物。用变温X-射线结构分析研究了碘桥直链结构铂二聚体配合物的相变，并通过电化学氧化法制备了一种新的卤素桥一维Ni^<III>-Br-Ni^<III>化合物{[Ni（en）_2Br]（ClO_4）_2}_*（en=C_2H_8N_2）的两种晶型（α和β）。X-射线晶体结构分析表明，Br离子桥连在两个Ni原子之间的中点上，并且通过引入大体积的ClO_4 ~（2-）离子作为c阴离子，Ni-Br键的距离为2.640（1）*。安街 ...更多信息 从沿着链的晶格参数可以估计β形式的2.693（2）* 的Rage Ni-Br距离。磁化率数据表明，线性链上Ni_（1-x）上的电子自旋（S=1/2）之间存在强的反铁磁耦合（J=-1700K）<III>，具有MMX型线性链结构的卤素桥联混合价化合物Pt_2（dta）_4I（dta=CH_3CS_2^-）在300 ~ 340 K之间表现出金属导电性，这在卤素桥联一维金属配合物中尚属首次。用单晶衍射法测量了Pt_2（dta）_4I在-160-190 ℃温度范围内的晶格参数，发现在一级（约90 ℃）和二级（约0 ℃）相变中存在沿着的反常滞后现象。使用安装在Enraf-cad 4衍射仪上的成像板检测器在-89-130 ℃范围内的几个温度下进行了晶体结构分析。空间群为A2/m的高温相的晶体结构显示出dta配体中S原子的配位无序，这可能是由于Pt_2（dta）_4I单元的扭曲运动造成的，而C2/c的低温相没有这种无序。通过对中间相位置无序的分析，发现存在一种提高Pt-Pt键伸缩幅度的分子构象。Pt_2（dta）_4单元的扭曲热运动是一维混合价体系中电子-声子耦合的基本现象，它导致了铂二聚体单元之间的电子转移。少

项目成果

Yoshiki Ozawa: "Electrochemical Synthesis and Crystal Structure of a Novel One-Dimensional Halogen-Bridged Nickel(III)Complex" Chem.Letters. 1995. 257-258 (1995)

Yoshiki Ozawa：“新型一维卤素桥镍（III）络合物的电化学合成和晶体结构”Chem.Letters。

Y.Ozawa: "Electrocrystallization,Crystal Structure,and Solid State Properties of Halogen-Bridged One-Dimensional Compound,{Ni(en)_2Br](ClO_4)_2}_∞,Having an Elongated Ni…Ni Distance" Mol.Cryst.Liq.Cryst.278. 189-197 (1996)

Y.Ozawa：“卤素桥一维化合物的电结晶、晶体结构和固态性质，{Ni(en)_2Br](ClO_4)_2}_∞，具有拉长的 Ni…Ni 距离”Mol.Cryst。液体晶体.278。189-197 (1996)

Y.Ozawa and K.Toriumi: ""Electrical Synthesis and Crystal Structure of a Novel One-Dimensional Halogen-Bridged Nickel(III) Complex"" Chem.Letters. 1995. 257-258 (1995)

Y.Ozawa 和 K.Toriumi：“新型一维卤素桥镍 (III) 配合物的电合成和晶体结构”，Chem.Letters。

M.Yamashita: "Halogen‐Bridged One‐DimensionalNi^<II>-Ni^<IV> Mixed‐Valence State and Ni^<III>" Synthetic Metals. 55-57. 3461-3468 (1993)

M. Yamashita：“卤素桥接一维 Ni^<II>-Ni^<IV> 混合价态和 Ni^<III>”合成金属。55-57 (1993)

K.Inoue, M.Yamashita, T.Furuta, A.Ichikawa, T.Ohishi, H.Okamoto, N.Kimura, H.Ohki, R.Ikeda, S.Bandow, K.Toriumi, T.Mitani, H.Kitagawa, and H.Miyamae: ""Structural Control of Quasi-One-Dimensional Halogen-Bridged Nickel Complexes"" Synthetic Metals. 71. 19

K.Inoue、M.Yamashita、T.Furuta、A.Ichikawa、T.Ohishi、H.Okamoto、N.Kimura、H.Ohki、R.Ikeda、S.Bandow、K.Toriumi、T.Mitani、H.