Wakizaka Masanori, Mian Mohammad Rasel, Yoshida Takefumi, Sato Tetsu, Tanaka Hisaaki, Miyamoto Tatsuya, Okamoto Hiroshi, Takaishi Shinya, Iguchi Hiroaki, Yamashita Masahiro
Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Aoba-Ku, Sendai 980-8578, Japan.
Department of Applied Physics, Graduate School of Engineering, Nagoya University, Chikusa-Ku, Nagoya 464-8603, Japan.
Inorg Chem. 2022 Jun 27;61(25):9504-9513. doi: 10.1021/acs.inorgchem.2c00473. Epub 2022 Jun 13.
Halogen-bridged linear chain metal complexes (MX-Chains) are fascinating compounds that have a quasi-one-dimensional (1D) electronic system. In this study, we synthesized the first Ni-based MX-Chain compound having hydroxy groups, i.e., [Ni(dabdOH)Br]Br·[Ni(dabdOH)Br]·(2-PrOH)·(MeOH) (·solvent, = ∼0.6, dabdOH = (2,3)-2,3-diaminobutane-1,4-diol). Single-crystal X-ray diffraction revealed that the MX-Chains in ·solvent formed sheets and single-chain structures in the superlattice. It suggested an MH-like state, whereas the polarized reflection and Raman spectra suggested a CDW-like state. Magnetic and electron spin resonance measurements revealed that both high-spin Ni(II) (∼15%) and low-spin Ni(III) (∼85%) sites are present in the chain structures, i.e., the metal sites show mixed valency. Therefore, we concluded that ·solvent adopts an intermediate state between the MH and CDW states. Moreover, a single crystal of ·solvent exhibited semiconductive characteristics along the chain direction. This finding represents a new structural and electronic state of 1D electronic systems as well as MX-Chains.
卤素桥连线性链金属配合物（MX链）是具有准一维（1D）电子系统的迷人化合物。在本研究中，我们合成了首例含羟基的镍基MX链化合物，即[Ni(dabdOH)Br]Br·[Ni(dabdOH)Br]·(2-PrOH)·(MeOH)（·溶剂， = ∼0.6，dabdOH = (2,3)-2,3-二氨基丁烷-1,4-二醇）。单晶X射线衍射表明，·溶剂中的MX链在超晶格中形成了片层和单链结构。这表明存在类MH态，而偏振反射光谱和拉曼光谱表明存在类CDW态。磁性和电子自旋共振测量表明，链结构中同时存在高自旋Ni(II)（约15%）和低自旋Ni(III)（约85%）位点，即金属位点呈现混合价态。因此，我们得出结论，·溶剂处于MH态和CDW态之间的中间态。此外，·溶剂的单晶沿链方向表现出半导体特性。这一发现代表了一维电子系统以及MX链的一种新的结构和电子态。
