Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS─Université de Rennes 1─INSA de Rennes, 11 allée de Beaulieu, CS 50837, 35708 Rennes Cedex, France.
Inorg Chem. 2023 Apr 17;62(15):6011-6019. doi: 10.1021/acs.inorgchem.2c04518. Epub 2023 Apr 5.
Powder samples of the new monoclinic compounds LnMoSiO (Ln = La, Ce, Pr, and Nd) and single crystals of PrMoSiO were obtained by the solid-state reaction. The crystal structure of PrMoSiO was determined by single-crystal X-ray diffraction. PrMoSiO crystallizes in the monoclinic space group 2/ with unit-cell parameters = 5.6361 (2) Å, = 17.5814 (8) Å, = 10.9883 (4) Å, and = 4. Full-matrix least-squares refinement on using 7544 independent reflections for 203 refinable parameters results in = 0.0359 and w = 0.0831. The structure contains chains of MoO clusters and chains of edge-sharing MoO octahedra with alternately short (2.508 Å) and long (3.161 Å) Mo-Mo distances running parallel to the axis that are separated by 8- or 10-coordinate Pr-O polyhedra. Magnetic susceptibility measurements on the LnMoSiO (Ln = La, Ce, Pr, and Nd) are in agreement with a trivalent state of the rare earths for the Ce, Pr, and Nd compounds, while that on the lanthanum compound confirms the presence of one unpaired electron per Mo as expected. Resistivity measurements on a single crystal show that PrMoSiO is a small band gap semi-conductor.
通过固态反应获得了新的单斜化合物 LnMoSiO（Ln = La、Ce、Pr 和 Nd）的粉末样品和 PrMoSiO 的单晶。PrMoSiO 的晶体结构通过单晶 X 射线衍射确定。PrMoSiO 结晶于单斜空间群 2/，具有单元参数 = 5.6361（2）Å、 = 17.5814（8）Å、 = 10.9883（4）Å 和 = 4。使用 7544 个独立反射对 203 个可精修参数进行全矩阵最小二乘精修，得到 = 0.0359 和 w = 0.0831。结构包含 MoO 簇链和 MoO 八面体链，具有交替的短（2.508 Å）和长（3.161 Å）Mo-Mo 距离，平行于 轴，由 8 或 10 配位的 Pr-O 多面体隔开。LnMoSiO（Ln = La、Ce、Pr 和 Nd）的磁化率测量结果与 Ce、Pr 和 Nd 化合物的三价稀土一致，而镧化合物的磁化率则证实了每个 Mo 都存在一个未配对的电子，这是预期的。单晶的电阻率测量表明 PrMoSiO 是一种小带隙半导体。
