In:
Zeitschrift für anorganische und allgemeine Chemie, Wiley, Vol. 635, No. 12 ( 2009-10), p. 1940-1946
Abstract:
The two new compounds Er 3 OFS 3 and Er 3 OF 3 S 2 vary mostly in their fluoride and sulfide content. The fluoride‐poor erbium(III) oxide fluoride sulfide Er 3 OFS 3 crystallizes in the tetragonal space group I 4/ mmm ( a = 374.86(2), c = 2068.41(9) pm, Z = 2) with two crystallographically different Er 3+ cations. (Er1) 3+ is surrounded by six S 2– anions in the shape of a slightly distorted octahedron, whereas (Er2) 3+ exhibits a coordination number of eight (4 × O 2– /F – and 4 × S 2– arranged as a square antiprism). In the crystal structure of Er 3 OFS 3 edge‐sharing tetrahedral [ZEr 4 ] 10.5+ units (Z n – = 50 % O 2– + 50 % F – ) form condensed {}^2_\infty [OFEr 2 ] 3+ layers. These layers alternate with {}^2_\infty [ErS 3 ] 3– sheets, built up of [ErS 6 ] 9– octahedra, which are connected through four common edges, to complete the three‐dimensional crystal structure of Er 3 OFS 3 . The fluoride‐rich erbium(III) oxide fluoride sulfide Er 3 OF 3 S 2 crystallizes in the orthorhombic space group Ccce ( a = 538.31(2), b = 1892.03(9), c = 538.27(2) pm, Z = 4). Two crystallographically distinct Er 3+ cations are present in its crystal structure. (Er1) 3+ is surrounded by eight Z n – anions (Z = 25 % O 2– + 75 % F – ) in the shape of a twisted square antiprism, whereas (Er2) 3+ holds a coordination number of nine (4 × O 2– /F – and 5 × S 2– arranged as a monocapped square antiprism), copying the arrangement around the Er 3+ cations in PbFCl‐type ErFS. The three‐dimensional structure of Er 3 OF 3 S 2 is built up of S 2– sheets and {}^2_\infty [OF 3 Er 3 ] 4+ double layers, which are formed by strongly contorted tetrahedral [ZEr 4 ] 10.75+ units (Z n – = 25 % O 2– + 75 % F – ). The crystals of this compound show a prominent superstructure in the tetragonal space group I 4/ mmm with a = 380.59(3), c = 1892.03(9) pm and Z = 2. In the crystal structures of both title compounds, the light anions O 2– and F – occupy one crystallographically unique Wyckoff position in a statistic allocation. Subject to the O/F content in the formulae, the ratio of O 2– :F – is 1:1 in Er 3 OFS 3 and 1:3 in Er 3 OF 3 S 2 .
Type of Medium:
Online Resource
ISSN:
0044-2313
,
1521-3749
DOI:
10.1002/zaac.v635:12
DOI:
10.1002/zaac.200900188
Language:
English
Publisher:
Wiley
Publication Date:
2009
detail.hit.zdb_id:
201094-X
detail.hit.zdb_id:
1481139-X
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