Electrochemical synthesis, crystal structure, and photomagnetic properties of a three-dimensional cyano-bridged copper-molybdenum complex.
Electrochemical synthesis, crystal structure, and photomagnetic properties of a three-dimensional cyano-bridged copper-molybdenum complex.
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DOI：
10.1021/ja044107o
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发表时间：
2005-02
影响因子：
15
通讯作者：
T. Hozumi;K. Hashimoto;S. Ohkoshi
中科院分区：
文献类型：
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作者：
T. Hozumi;K. Hashimoto;S. Ohkoshi
在铂丝电极上电化学制备 Cs(I)2Cu(II)7[Mo(IV)CN8]4.6H2O 单晶，恒电位为 +500 mV（相对于 Ag/AgCl 电极）。 X射线单晶结构分析表明，该化合物由三维氰基桥联的Cu-Mo双金属组装体组成，具有I4/mmm的四方结构。 Mo(IV)的配位几何为双帽三棱柱，Cu(II)的配位几何为五配位正方锥体或四配位正方平面。该化合物还以相同的电化学方式在 SnO2 涂层玻璃上制备成 0.2-3.0 微米厚的薄膜。当样品因 Cu(II) (S = 1/2) 而表现出顺磁性时，在 5 K 下用 450-500 nm 光照射时，观察到居里温度为 23 K 的自发磁化。这种光诱导的变化通过热处理得以恢复。在光照射后的红外（IR）和电子自旋共振（ESR）光谱中，分别观察到桥接Mo（IV）的CN的伸缩IR峰和Cu（II）的顺磁ESR峰的变化。数据表明，这种光磁性是由从 Mo(IV) 到 Cu(II) 的电子转移以及 Cu(II) (S = 1/2) 和 Mo(V) (S = 1/2) 之间的铁磁排序引起的。
A single crystal of Cs(I)2Cu(II)7[Mo(IV)CN8]4.6H2O was electrochemically prepared on a Pt wire electrode with a constant potential of +500 mV vs Ag/AgCl electrode. X-ray single-crystal structural analysis showed that this compound consists of a three-dimensional cyano-bridged Cu-Mo bimetallic assembly with a tetragonal structure of I4/mmm. The coordination geometry of Mo(IV) is bicapped trigonal prism, and that of Cu(II) is five-coordinate of square pyramidal or four-coordinate of square planar. This compound was also prepared as a 0.2-3.0 microm thick film on a SnO2-coated glass in the same electrochemical manner. When the sample, which shows paramagnetism due to Cu(II) (S = 1/2), was irradiated with 450-500 nm light at 5 K, spontaneous magnetization with a Curie temperature of 23 K was observed. This photoinduced change was recovered by a thermal treatment. In the infrared (IR) and electron spin resonance (ESR) spectra after light irradiation, variations in the stretching IR peak of CN bridged to Mo(IV) and the paramagnetic ESR peak of Cu(II) were observed, respectively. The data indicate that this photomagnetism is caused by the electron transfer from Mo(IV) to Cu(II) and the ferromagnetic ordering between Cu(II) (S = 1/2) and Mo(V) (S = 1/2).