BaCeN₂, ein Bariumnitridocerat(IV) mit einer Struktur vom anti-TiP-Typ / BaCeN₂, a Bariumnitridocerate(IV ) with a Structure of the anti-TiP Type

Abstract

Reaction of Ba3N2 with CeN in the stoichiometric ratio 1:3 at 850 °C under an atmosphere of N2 followed by quenching yields air and moisture sensitive BaCeN2. The product crystallizes isotypically to β-RbScO2 with the anti-TiP type structure in the hexagonal space group P63/mmc with a = 365.06(2), c = 1266.03(3) pm, Z = 2. The structure was determined using X-ray and neutron powder diffraction data. In the structure the Ba2+ cations occupy trigonal prismatic holes with distances Ba-N = 288(1) pm while the Ce atoms are in octahedral positions with distances C e -N = 242.4(8) pm

Synthesis, Structure, and Magnetic Properties of the New Ternary Nitride BaHfN2and of the BaHf1−xZrxN2Solid Solution

“…The mean Ba-N bond length, including the four longer distances, is 3.184(3) A s , whereas, excluding these distances, it is more reasonably 2.874(4) A s . This distance is of the same order as those seen in other barium ternary nitrides (e.g., 2.88(1) A s in BaCeN (19) and a mean distance of 2.914(5) A s in Ba CrN (23)). The distances agree well with the mean values calculated from those bond lengths previously reported for BaZrN (3.212(3) and 2.913(3) A s including and excluding the longer Ba-N distances, respectively) (20).…”

“…BaCeN possesses a layered structure and is isostructural with -RbScO (19). BaZrN is isotypic with KCoO , which contains layers made up of edge-sharing Zr-N square-base pyramids (20).…”

New Ternary Alkaline Earth Metal Cerium(IV) Nitrides: CaCeN2 and SrCeN2Dedicated to Professor Welf Bronger on the Occasion of his 70th Birthday

“…The distances d(SrϪN) are comparable to those in Sr 2 N (261.2 pm) with Sr in three-fold coordination by nitrogen [33]. The distance d (CeϪN) is nearly the same as in BaCeN 2 determined from neutron diffraction (242.7 pm) [23] and slightly shorter than reported for Li 2 CeN 2 (253.3 pm) [22]. Different interlayer distances in LT-SrCeN 2 between two adjacent nitrogen slabs of 349.2 pm and 249.4 pm are due to the differences in ionic radii of Sr 2ϩ and Ce 4ϩ .…”

“…Clarke and DiSalvo [21] reported a defect rocksalt nitride phase (Ca x La 1Ϫx )N 1Ϫx/3 (0 < x < 0.7) and two ternary cerium compounds are known: Li 2 CeN 2 [22] and BaCeN 2 [23]. In the layered crystal structures of Li 2 CeN 2 and BaCeN 2 cerium ions are surrounded by octahedra of nitrogen, but, as expected, the coordination environments of Li and Ba are quite different.…”

Gallium Pnictides of the Alkaline Earth Metals, Synthesized by Means of the Flux Method: Crystal Structures and Properties of CaGa2Pn2, SrGa2As2, Ba2Ga5As5, and Ba4Ga5Pn8 (Pn = P or As)

“…For instance, CaGa 2 P 2 , CaGa 2 As 2 , and SrGa 2 As 2 can all be readily derived from a simple close-packed structure, such as TiAs (or its ternary variant, the AlCr 2 C type, space group P6 3 /mmc; Pearson symbol hP8). [38] In this structural arrangement, exemplified by BaCeN 2 [39] in Figure 4, the pnictogen atoms form a double hexagonal close-packed (hcp) array, with trigonal prismatic and octahedral holes occupied by Ba and Ce, respectively. Similarly, the CaGa 2 P 2 structure can be viewed as a double hcp array of P 3-, which forms the same trigonal prisms and regular octahedra.…”