Three New Lanthanum Oxoantimonate(III) Halides: Synthesis and Crystal Structure of La5Cl3[SbO3]4, La2Sb12O19Br4 and La2Sb12O19I4

• Published in: Crystals (Basel) Vol. 13; no. 5; p. 731
• Main Authors: Locke, Ralf, Bozenhardt, Kim-Natalie, Goerigk, Felix, Schleid, Thomas
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.05.2023
• Subjects: Aluminum; Anions; Crystal structure; crystal structures; Fluorides; Halides; Lanthanum; Lattice parameters; oxoantimonates(III); Oxygen atoms; Raman spectra; Single crystals; Spectrum analysis; Japan; Germany
• ISSN: 2073-4352; 2073-4352
• DOI: 10.3390/cryst13050731

It was possible to synthesize colorless single crystals of La5Cl3[SbO3]4 (block-shaped) as well as La2Sb12O19Br4 and La2Sb12O19I4 (both needle-shaped), representing three new compounds from the system of lanthanum oxoantimonate(III) halides, which have not been described in the literature before. La5Cl3[SbO3]4 crystallizes in the monoclinic space group P2/c with the lattice parameters a = 895.82(5) pm, b = 564.28(3) pm, c = 1728.19(9) pm, and β = 90.007(2)° for Z = 2. This layered compound contains isolated ψ1-tetrahedral [SbO3]3– units, square hemiprisms [LaO8]13–, and antiprisms [LaO4Cl4]9−. La2Sb12O19Br4 and La2Sb12O19I4 crystallize isotypically in the orthorhombic space group Pnma with a = 3184.69(19) pm, b = 417.78(3) pm, c = 1019.85(6) pm for the bromide and a = 3215.08(19) pm, b = 419.94(3) pm, c = 1062.89(6) pm for the iodide. Instead of isolated [SbO3]3− anions, semi-tubular features 1∞{[Sb12O19]2−} are present, which consist mainly of [SbO4]5− and few [SbO3]3− units with stereochemically active electronic lone pairs at their Sb3+ centers. Within these so-called “double-halfpipes”, La3+ is surrounded by nine oxygen atoms as [LaO9]15– polyhedron without any contact with X− anions. Single-crystal Raman measurements were performed for La5Cl3[SbO3]4 and La2Sb12O19I4, and La5Cl3[SbO3]4 was structurally compared with the isostoichiometric, but not isotypic La5F3[SbO3]4.