New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research , Jakkur, Bangalore, 560064 India.
Inorg Chem. 2014 Jan 6;53(1):653-60. doi: 10.1021/ic402858u. Epub 2013 Dec 23.
A new organic-inorganic hybrid material SiMo14O442·xH2O (4,4'-bpy = 4,4'-bipyridine) was synthesized using a hydrothermal method. The compound was characterized using single crystal X-ray diffraction (XRD), infrared spectroscopy (IR), ultraviolet-visible spectroscopy (UV-vis), and X-ray photoelectron spectroscopy (XPS). XRD studies on selected single crystals suggested that the compound consists of supramolecular 2D layer structures composed of capped α-Keggin polyoxomolybdate anions and 4,4'-bpy organic ligands. Absorption measurements show a band gap of 2.99 eV in the hybrid which suggests a semiconducting nature compared to the insulating free α-Keggin and 4,4'-bpy. The magnetic susceptibility of the hybrid material was investigated in the temperature range 1.8-300 K obeying the Curie-Weiss law above 70 K. Experimentally measured magnetic moment of 2.71 μB/formula indicates possible mixed valent molybdenum in the compound. The XPS measurements confirm the presence of both Mo(V) and Mo(VI) in the ratio 15:85 resulting in the structural formula of the hybrid as SiMo(V)2Mo(VI)12O442·xH2O.
采用水热法合成了一种新型的有机-无机杂化材料SiMo14O442·xH2O（4,4'-bpy = 4,4'-联吡啶）。通过单晶 X 射线衍射（XRD）、红外光谱（IR）、紫外可见光谱（UV-vis）和 X 射线光电子能谱（XPS）对化合物进行了表征。对选定单晶的 XRD 研究表明，该化合物由具有封端α-Keggin 多钼酸盐阴离子和 4,4'-bpy 有机配体的超分子二维层状结构组成。吸收测量表明，杂化材料的带隙为 2.99 eV，与绝缘的游离α-Keggin 和 4,4'-bpy 相比，具有半导体性质。在 1.8-300 K 的温度范围内研究了杂化材料的磁化率，在 70 K 以上遵循居里-外斯定律。实验测量的 2.71 μB/分子式磁矩表明化合物中存在混合价态的钼。XPS 测量证实了混合相中 Mo(V)和 Mo(VI)的存在，比例为 15:85，导致杂化材料的结构公式为SiMo(V)2Mo(VI)12O442·xH2O。
