Sulfate und Hydrogensulfate des Erbiums: Er(HSO4)3-I, Er(HSO4)3-II, Er(SO4)(HSO4) und Er2(SO4)3

✍ Scribed by Mathias S. Wickleder

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: German
• Weight: 232 KB
• Volume: 624
• Category: Article
• ISSN: 0372-7874
• DOI: 10.1002/(sici)1521-3749(199808)624:8<1347::aid-zaac1347>3.0.co;2-w

✦ Synopsis

Inhaltsu È bersicht. Aus einer Lo È sung von Er 2 (SO 4 ) 3 in konz. H 2 SO 4 kristallisiert bei 250 °C Er(HSO 4 ) 3 -I (orthorhombisch, Pbca, a = 1195,0(1) pm, b = 949,30(7) pm, c = 1644,3(1) pm) in Form hellrosa sa È uliger Kristalle. Aus 85%iger H 2 SO 4 -Lo È sung, der Na 2 SO 4 zugesetzt wurde, erha Èlt man bei 250 °C hellrosa quaderfo È rmige Kristalle von Er(HSO 4 ) 3 -II (monoklin, P2 1 /n, a = 520,00( ) pm, b = 1357,8(1) pm, c = 1233,4(1) pm, b = 92,13(1)°) und bei ca. 60 °C Kristalle gleicher Farbe von Er(SO 4 )(HSO 4 ) (monoklin, P2 1 /n, a = 545,62(6) pm, b = 1075,6(1) pm, c = 1053,1(1) pm, b = 104,58(1)°). In beiden Hydrogensulfaten ist Er 3+ von acht Sauerstoffatomen umgeben. In Er(HSO 4 ) 3 -I werden Schichten von HSO 4 ± -Tetraedern ausschlieûlich u È ber Wasserstoffbru È cken zusammengehalten, wa È hrend bei Er(HSO 4 ) 3 -II die Polyeder dreidimensional vernetzt sind. In der Kristallstruktur von Er(SO 4 )(HSO 4 ) ist Er 3+ von sieben Sauerstoffatomen umgeben, die zu vier SO 4 2± -und drei HSO 4 ± -Gruppen geho È ren. Das wasserfreie Sulfat, Er 2 (SO 4 ) 3 , ist nicht aus H 2 SO 4 -Lo È sungen zuga È nglich, kann jedoch einkristallin aus einer NaCl-Schmelze erhalten werden. Die Koordinationszahl von Er 3+ in Er 2 (SO 4 ) 3 (orthorhombisch, Pbcn, a = 1270,9(1) pm, b = 913,01(7) pm, c = 921,67(7) pm) ist sechs, die oktaedrischen Koordinationspolyeder sind u È ber alle Ecken mit SO 4 2± -Tetraedern verknu È pft. Sulfates and Hydrogensulfates of Erbium: Er(HSO 4 ) 3 -I, Er(HSO 4 ) 3 -II, Er(SO 4 )(HSO 4 ), and Er 2 (SO 4 ) 3 Abstract. Rod shaped light pink crystals of Er(HSO 4 ) 3 -I (orthorhombic, Pbca, a = 1195.0(1) pm, b = 949.30(7) pm, c = 1644.3(1) pm) grow from a solution of Er 2 (SO 4 ) 3 in conc. H 2 SO 4 at 250 °C. From slightly diluted solutions (85%) which contain Na 2 SO 4 , brick shaped light pink crystals of Er(HSO 4 ) 3 -II (monoclinic, P2 1 /n, a = 520.00(5) pm, b = 1357.8(1) pm, c = 1233.4(1) pm, b = 92.13(1)°) were obtained at 250 °C and crystals of the same colour of Er(SO 4 )(HSO 4 ) (monoclinic, P2 1 /n, a = 545.62(6) pm, b = 1075.6(1) pm, c = 1053.1(1) pm, b = 104.58(1)°) at 60 °C.

In both hydrogensulfates, Er 3+ is surrounded by eight oxygen atoms. In Er(HSO 4 ) 3 -I layers of HSO 4 ± groups are connected only via hydrogen bridges, while Er(HSO 4 ) 3 -II consists of a threedi-mensional polyhedra network. In the crystal structure of Er(SO 4 )(HSO 4 ) Er 3+ is sevenfold coordinated by oxygen atoms, which belong to four SO 4 2± -and three HSO 4 ± -tetrahedra, respectively. The anhydrous sulfate, Er 2 (SO 4 ) 3 , cannot be prepared from H 2 SO 4 solutions but crystallizes from a NaCl-melt. The coordination number of Er 3+ in Er 2 (SO 4 ) 3 (orthorhombic, Pbcn, a = 1270.9(1) pm, b = 913.01(7) pm, c = 921.67(7) pm) is six. The octahedral coordinationpolyhedra are connected via all vertices to the SO 4 2± -tetrahedra.