Schurz Christian M, Schleid Thomas, Meyer Gerd
Acta Crystallogr Sect E Struct Rep Online. 2010 Nov 10;66(Pt 12):i78. doi: 10.1107/S1600536810045198.
The ternary title compound, dipotassium lanthanum penta-chloride, K(2)LaCl(5), is isotypic with Y(2)HfS(5) and various ternary rare-earth metal(III) halides with the general formula A(2)MX(5) (A = NH(4), In(I), Na-Cs; M = La-Dy; X = Cl-I). The La(3+) cations and three of the four symmetry-independent chloride anions are located on a crystallographic mirror plane. The La(3+) cations are surrounded by seven chloride anions, each in the shape of a monocapped trigonal prism, whereas the coordination spheres of the K(+) cations exhibit one more cap. Three of the four independent chloride anions reside in a fivefold cationic coordination, leading to distorted square pyramids. The fourth chloride anion has only four cationic neighbours, forming no specific polyhedron.
三元标题化合物五氯化镧二钾（K₂LaCl₅）与Y₂HfS₅以及各种通式为A₂MX₅（A = NH₄、In(I)、Na - Cs；M = La - Dy；X = Cl - I）的三元稀土金属(III)卤化物同晶型。La³⁺阳离子和四个对称独立的氯离子中的三个位于一个晶体学镜面平面上。La³⁺阳离子被七个氯离子包围，每个氯离子呈单帽三角棱柱形状，而K⁺阳离子的配位球多一个帽。四个独立氯离子中的三个处于五重阳离子配位中，形成扭曲的四方金字塔。第四个氯离子只有四个阳离子邻居，不形成特定的多面体。
