Sm3Cl[SiO4]2: Ein chlorarmes Chloridorthosilicat des Samariums

Abstract

Sm3Cl[SiO4]2: A Chlorine‐poor Chloride Orthosilicate of Samarium Pale yellow, plate‐like single crystals of Sm3Cl[SiO4]2 (orthorhombic, Pnma; a = 701.74(8), b = 1800.8(2), c = 626.63(7) pm; Z = 4) are obtained upon the reaction of SmCl3, Sm2O3 and SiO2 (”︁Kieselgel”︁”︁) in 1 : 4 : 6 molar ratios, most advantageously in the presence of substantial amounts of NaCl as fluxing agent, after seven days at 850 °C in evacuated silica ampoules. The B‐type crystal structure (isotypic with e. g. Yb3Cl[SiO4]2) contains discrete orthosilicate tetrahedra [SiO4]4– which form anionic double layers ({(Sm1)2[SiO4]2}2–) with (Sm1)3+. These are alternatingly sheethed along [010] with cationic monolayers ({(Sm2)Cl}2+) consisting of (Sm2)3+ and Cl–. Both crystallographically independent Sm3+ cations exhibit coordination numbers of eight (Sm1: 1 Cl + 7 O; Sm2: 2 Cl + 6 O) with respect to the involved electronegative particles.

Inorganic Lanthanide Compounds with Complex Anions

“…Halide ortho -silicates of the rare-earth elements are mainly known with Cl - as the halide component. Those with the composition M 3 Cl(SiO 4 ) 2 crystallize either in a monoclinic (A-type) or an orthorhombic (B-type) modification. − The A-type occurs with the larger M 3+ ions and the B-type with the smaller ones (cf. Table ).…”

“…Those with the composition M 3 Cl(SiO 4 ) 2 crystallize either in a monoclinic (A-type) or an orthorhombic (B-type) modification. [23][24][25][26][27][28][29] The A-type occurs with the larger M 3+ ions and the B-type with the smaller ones (cf. Table 1).…”

“…A huge number of rare-earth ortho-silicates can be derived from the structure of the mineral fluoroapatite, Ca 5 (PO 4 ) 3 F, [37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55] (Table 1). As can be seen from the scheme in Figure 6, the structure is retained when the SiO 4 4ion is placed for PO 4 3and Fis substituted for O 2-.…”

“…117 It was obtained as a side product during the chemical transport of SmS 2 with I 2 in silica ampules. To date a number of isotypic compounds were obtained, either with larger or smaller M 3+ ions and with S 2or Se 2as chalcogenide anion [117][118][119][120][121][122][123][124] (Table 2). They all contain two crystallographically different M 3+ ions which are in 8-fold and 9-fold coordination, respectively.…”

Photoluminescent Layered Lanthanide Silicate Nanoparticles

“…Several lanthanide silicates with the Clions interacting with four or more Ln 3+ centers are known. [20][21][22][23] The present family of materials is indeed unique because it consists of the first stoichiometric layered silicates containing chloride in the coordination sphere of a single Ln 3+ ion.…”