Renaissance of the Stella Quadrangula: The Lanthanoid Nitride Tellurides Ln₁₃N₅Te₁₂ (Ln = La–Nd)

Abstract

Ln 13 N 5 Te 12 (Ln = La-Nd), a quite unusual composition of the lanthanoid(III) nitride tellurides, appears with a new crystal structure and can be obtained by reactions of lanthanoid metal (Ln) with elemental tellurium (Te), sodium azide (NaN 3 ), elemental iodine (I 2 ) and sodium iodide (NaI) as flux in evacuated fused silica tubes for seven days at 900°C. The black, shard-shaped single crystals of the short new series Ln 13 N 5 Te 12 (Ln = La-Nd) crystallize monoclinically in the space group P2 1 /m with lattice parameters ranging from a = 1039.86 (7), b = 1373.29(9), c = 1311.78(9) pm, = 100.103(3)°for La 13 N 5 Te 12 to a = 1016.73 (7), b = 1337.58 (9), c = 1288.92(9) pm, = 100.094(3)°for Nd 13 N 5 Te 12 and Z = 2. Unlike the other ternary [a]

About Lanthanoid Fluoride Selenide Oxoselenotantalates with the Composition Ln3F2Se2TaO4 (Ln = La – Nd)

“…In the hexagonal Ln 2 OF 2 Se and Ln 6 O 2 F 8 Se 3 series there is also a structural change at the neodymium compounds, which are published with both stoichiometries and structures. [16] For the oxide-poor tetragonal oxide selenides Ln 10 OSe 14 only the compounds with Ln = La -Nd seem to exist [28][29][30] and only the lanthanoids Ln = La -Nd form the nitride tellurides Ln 13 N 5 Te 12 [31] or the nitride bismuthides Ln 2 NBi. [32] With oxoselenate(IV) anions the Ln 2 O[SeO 3 ] 2 series starts with the samarium compound as the first one of the lanthanoids [33,34] [35] has a unique structure and the rest of the LnCl[SeO 3 ] [35][36][37][38] series starts with Ln = Sm again.…”