In:
Chemistry – A European Journal, Wiley, Vol. 23, No. 63 ( 2017-11-13), p. 16034-16043
Abstract:
Anhydrous hydroxide sulfates Ln 2 (OH) 4 SO 4 (Ln=Eu–Lu, Y) were hydrothermally synthesized as a new family of layered rare earth metal hydroxides (LRHs). They crystallize in the monoclinic system (space group C 2/ m ) with structures built up by alternate stacking of interlayer SO 4 2− and the two‐dimensional host layer composed of tricapped [LnO 9 ] trigonal prisms along the a axis. In distinct contrast to the recently discovered hydrated LRHs Ln 2 (OH) 4 SO 4 ⋅ 2 H 2 O, which only exist for Ln=La–Dy, the host layers of the anhydrous phase are linked together by sharing edges instead of an O node of the SO 4 2− tetrahedron. Rietveld refinement showed that the cell dimension tends to decrease for smaller Ln 3+ , while the axis angle ( β =98.78–100.31°) behaves oppositely. Comparative thermogravimetric/differential thermal analysis in air revealed that the dehydroxylation and desulfurization temperatures become gradually higher and lower, respectively, for smaller Ln 3+ , and thus the temperature range of Ln 2 O 2 SO 4 existence is narrowed. The newly discovered Ln 2 (OH) 4 SO 4 , together with their hydrated counterparts, allow for the first time green synthesis of Ln 2 O 2 SO 4 with water as the only exhaust for the full spectrum of lanthanides. Calcining Ln 2 (OH) 4 SO 4 in H 2 yielded phase‐pure Ln 2 O 2 S for Eu and Gd and a mixture of Ln 2 O 2 S and Ln 2 O 3 for the other Ln. The effects of the lanthanide contraction were clearly revealed, and photoluminescence was found for the anhydrous LRHs of Eu and Tb.
Type of Medium:
Online Resource
ISSN:
0947-6539
,
1521-3765
DOI:
10.1002/chem.201703282
Language:
English
Publisher:
Wiley
Publication Date:
2017
detail.hit.zdb_id:
1478547-X
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