A New Europium(II) Oxide Iodide: Eu₂OI₂

Abstract

Red single crystals of Eu 2 OI 2 were obtained from a reaction mixture of barium metal, EuI 2 , Eu 4 OI 6 and some NH 4 I in a tantalum tube at 780/500°C. The crystal structure (orthorhombic, Imcb, Z ϭ 4, a ϭ 648.93 (11), b ϭ 742.85(13), c ϭ 1307.1(3) pm, R1(all) ϭ 0.0605) contains {Eu 4 O} tetrahedra connected via trans-Deutsche Forschungsgemeinschaft, Bonn (Schwerpunktprogramm "Lanthanoid-spezifische Funktionalitäten") and by the State of Nordrhein-Westfalen and the Universität zu Köln.

Chains of trans-edge connected [ZM4] tetrahedra (Z=N and O) in the lanthanide nitride chlorides M2NCl3 and Na2M4ONCl9 (M=La–Nd)

“…They share transedge connected [ZM 4 with the M 2 NCl 3 -type compounds as the same dominating structural feature, which are identical to anti-SiS 2 -analogous chains [8]. Such chains of tetrahedra can also be observed in M 2 NBr 3 (M = Ce, Gd) [9,10], M 4 N 2 Te 3 (M = La-Nd) [11,12] and, in close relation, in Eu 2 OI 2 [13] with divalent europium for the oxygen case. Essentially, [ZM 4 ] tetrahedra serve also as an attribute to the M 3 NCl 6 edge connected, c: corner connected) [14].…”

Alkaline Earth Metal Oxyhalides Revisited – Syntheses and Crystal Structures of Sr4OBr6, Ba4OBr6 and Ba2OI2

“…Recently the 'pseudo' alkaline earth metal oxyhalide Eu 2 OI 2 [1] was synthesized and found to adopt the antitype of the well-known oxide K 2 ZnO 2 [2]. A few weeks later we found by serendipity Sr 2 OI 2 [3] which is -not too surprisingly -isotypic to Eu 2 OI 2 .…”