Zur Kenntnis von Hydridhalogeniden MHX der Seltenen Erden Eu, Yb und Sm (X = Cl, Br, I) / A Study on Hydride Halide Compounds MHX of the Rare Earths Eu,Yb, and Sm (X = Cl,Br,I)

Abstract

<jats:p>New hydride halide compounds MHX (M = Eu, Yb, Sm; X = Cl, Br, I) of divalent rare earths have been prepared by solid-state reactions. Lattice parameters and X-ray diffraction patterns are presented for these compounds. All compounds are isostructural with tetragonal PbFCl. Refined lattice parameters of alkaline earth hydride halides are given. The crystal chemistry of MHX and MFX is compared and the geometric variations in the structure of these compounds are interpreted on the basis of changes in covalency</jats:p>

Recent Advances in Rare Earth‐Doped Hydrides

“…In the hydride chloride of divalent europium, EuHCl, crystallizing in the matlockite‐type structure (space group P 4/ nmm ), green broad band luminescence (maximum 510 nm) was observed . The europium cation is located inside a square antiprism formed by four hydride and five chloride anions and capped by one of the five chloride anions . The emission intensity was reported to be very high.…”

Synthesis and Crystal Structure of the Europium(II) Hydride Oxide Iodide Eu5H2O2I4 Showing Blue-Green Luminescence

“…The emission band decreases slowly with increasing wavelength, because of a further adjacent maximum resulting (Eu1) 2+ . This cation, being coordinated by four hydride and four iodide anions and surrounded by the most hydride anions of all three Eu 2+ cations in Eu5H2O2I4, should voke the widest red-shifted emission of the different Eu 2+ cations in this compound, an emission maximum at around 511 nm at 30 K. This is comparable with the emis wavelengths of the europium(II) hydride halides EuHCl (510 nm) [17], Eu2H3Cl (503 [18], and EuHBr (493 nm) [18], with similar coordination spheres and numbers, w EuHI [32] was never again obtained. Hence, its luminescence properties could not b termined.…”

“…The presence of a merohedral twin can be excluded due to symmetry considerations, however. The dark red colour of Eu5H2O2I4 does not surprise much, since it can be observed for pure hydride halides with heavy halogens (e.g., EuHBr [18,32] and Eu2H3X (X = Br [18,33] and I [18,34]) as well. 2, top, and Table 2, all distances mentioned in the text apply to the measurement 100 K).…”

Solid‐State Structures and Properties of Europium and Samarium Hydrides

“…Another example for the hydride fluoride analogy in ionic compounds is the class of the europium hydride halides EuHX (X = Cl, Br, I), for which the PbFCl‐type structure with hydrogen in a tetrahedral void was proposed 49. Europium may replace alkaline earth metals in complexhydrides also to form compounds such as Eu 2 FeH 6 ,Eu 2 RuH 6 , Eu 2 RhH 5 , EuMgNiH 4 , and EuMg 2 FeH 8 , which are presumably isostructural to their alkaline earthanalogues 50.…”