SYNTHESIS, CRYSTAL-STRUCTURE, AND PHYSICAL-PROPERTIES OF SR2N

Sr2N has been synthesized from the elements and its structure determined by time-of-flight neutron diffraction. Crystal data: R3m, a = 3.8566(1) Å, c = 20.6958(4) Å, V = 266.58(1) Å3, Z = 3, Dx = 2.13, T = 300 K, Rwp = 0.077, Rp = 0.056, reduced χ2 = 2.06 for 25,368 profile points and 53 variables. Sr2N crystallizes with the layered CdCl2 structure as formerly proposed. N atoms center flattened octahedra with six equal NSr distances of 2.6118(3) Å. The SrSr distances in the octahedral layer are 3.8566(1) (6x) and 3.523(1) (3x). The SrSr distances between layers are 4.726(1). It has been argued that Sr2N is actually Sr2NxHy; but the neutron data show the absence of any hydrogen contamination. Sr2N is a metallic conductor with a weak temperature-independent paramagnetism. © 1990.