Synthesis and structure of the new compound La2O(CN2)2 possessing an interchanged anion proportion compared to the parent La2O2(CN2)

La2O(CN2)(2) was synthesized from a 1:1:2 molar reaction mixture of LaCl3, LaOCl1 and Li-2(CN2) at 650 degrees C. Well developed single crystals were grown from a LiCl-KCl flux. The crystal structure was refined as monoclinic (space group C2/c, Z = 2, a = 13.530(2) angstrom, b = 6.250(1) angstrom, c = 6.1017(9) angstrom, beta = 104.81(2)degrees) from single crystal X-ray diffraction data. The La3+ and (CN2)(2-) ions in the crystal structure of La2O(CN2)(2) can be compared to Fe3+ 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 O2- ions in La2O(CN2)(2) are occupying 1/4 of the tetrahedral voids formed by the arrangement of metal ions.