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Synthesis and structure of lanthanide picrates with trans-1,3-dithiane-1,3-dioxide

2002; Elsevier BV; Volume: 344; Issue: 1-2 Linguagem: Inglês

10.1016/s0925-8388(02)00353-5

1873-4669

Paulo B. Miranda, J. Zukerman‐Schpector, P.C. Isolani, G. Vicentini, L.B. Zinner,

Luminescence Properties of Advanced Materials

Compounds with the formula [Ln(pic)3(trans-DTSO2)2] (Ln=La–Lu and Y) were obtained by reaction of hydrated lanthanide picrates with trans-1,3-dithiane-1,3-dioxide (trans-DTSO2) in absolute ethanol. Lanthanide contents were determined by titration with EDTA; CHN were determined by microanalytical procedures. Data are in good accordance with the proposed stoichiometry. IR absorption spectra were interpreted in terms of trans-DTSO2 and picrate anions coordinated through the oxygen atoms. The parameters obtained from the absorption spectrum of the Nd(III) compound indicate weakly covalent metal–ligand bonds. The emission spectrum obtained at 77 K for the Eu(III) compound suggests a C2v symmetry for the coordination polyhedron. X-Ray powder patterns show that the compounds are isomorphous. The structure of europium compound was determined by single crystal X-ray analysis and showed that the crystals are triclinic, space group P1̄, a=10.771(1) Å, b=12.243(1) Å, c=16.415(2) Å, α=99.930(10)°, β=103.970(10)°, γ=106.220(10)°. The compound exhibits a polymeric structure, in which two trans-DTSO2 are bridging the Eu(III) ions. The central ion is octacoordinated to four oxygens of trans-DTSO2 and four oxygens of one bidentate and two monodentate picrate anions, in a bicapped trigonal prism geometry, the dihedral angle between the bases being 14.2(1)o.