Synthesis and Structure of the New Compound La₂O(CN₂)₂ Possessing an Interchanged Anion Proportion Compared to the Parent La₂O₂(CN₂). Synthese und Kristallstruktur der neuen Verbindung La₂O(CN₂)₂ mit einem vertauschten Anionenverhältnis gegenüber der Bezugsverbindung La₂O₂(CN₂)

Abstract

Abstract La 2 O(CN 2 ) 2 was synthesized from a 1:1:2 molar reaction mixture of LaCl 3 , LaOCl, and Li 2 (CN 2 ) at 650 °C. Well developed single crystals were grown from a LiCl‐KCl flux. The crystal structure was refined as monoclinic (space group C 2/ c , Z = 2, a = 13.530(2) Å, b = 6.250(1) Å, c = 6.1017(9) Å, β = 104.81(2)°) from single crystal X‐ray diffraction data. The La 3+ and (CN 2 ) 2— ions in the crystal structure of La 2 O(CN 2 ) 2 can be compared to Fe 3+ and S 2 2— ions in the cubic pyrite structure, being arranged like in a distorted NaCl type structure with their centers of gravity. In addition, the O 2— ions in La 2 O(CN 2 ) 2 are occupying 1/4 of the tetrahedral voids formed by the arrangement of metal ions.