The Hydrothermal Synthesis, Crystal Structures and Thermal Stability of the Novel One- and Two-Dimensional Thioantimonate(III) Compounds [Co(tren)]Sb2S4 and [Ni(tren)]Sb2S4

Autor: Ralph Stähler, Wolfgang Bensch
Rok vydání: 2001
Předmět:
Zdroj: European Journal of Inorganic Chemistry. 2001:3073-3078
ISSN: 1099-0682
1434-1948
DOI: 10.1002/1099-0682(200112)2001:12<3073::aid-ejic3073>3.0.co;2-u
Popis: Two novel thioantimonate(III) compounds [Co(C6H18N4)]Sb2S4 (1) and [Ni(C6H18N4)]Sb2S4 (2) were synthesised under solvothermal conditions by reacting the transition metal, Sb and S in a 50% solution of tris(2-aminoethyl)amine (tren). The use of a tetradentate amine yields incompletely shielded transition metal cations which in turn are able to form bonds to the sulfur atoms of thioantimonate(III) anions. Compound 1 crystallises in the orthorhombic space group Pbca, a = 13.886(3) A, b = 11.452(2) A, c = 20.549(4) A, V = 3268(1) A3, Z = 8 and compound 2 crystallises in the monoclinic space group P21/n, a = 6.906(1) A, b = 22.822(5) A, c = 10.347(2) A, β = 103.17(3)°, V = 1587.9(6) A3, Z = 4. The 2∝[Sb2S42−] anion in compound 1 is formed by an SbS3 and an SbS4 unit sharing a common corner. Two SbS4 units have a common edge to form an Sb2S2 heterocycle. Four such Sb2S2 rings are at the corners of a two-dimensional square-like net. Interconnection of the rings by SbS3 pyramids yields Sb10S10 rings with pores measuring 10·8.4 A in diameter. The pores are filled by the [Co(tren)]2+ cations. The [Co]2+ cation is in a trigonal bipyramidal environment of four N atoms of the tren ligand and one S atom of the SbS3 pyramid. The one-dimensional 1∝[Sb2S42−] chain anion in 2 is built by two corner-sharing SbS3 units. The [Ni]2+ cation is in an octahedral environment consisting of four N atoms of the tren ligand and two S atoms of the anion. An NiSb2S3 heteroring in a twist conformation is formed with an unusually large Ni−S(1)−Sb(1) angle of 121.73(3)°. For the [Co]2+ (d7) cation no significant energy differences can be expected for the trigonal bipyramidal and octahedral coordination, and due to the geometrical requirements of the tetradentate ligand the former environment is preferred. In contrast, for [Ni]2+ (d8) an octahedral environment is energetically favoured over the trigonal bipyramidal arrangement. Both compounds start to decompose under an Ar atmosphere at about 250 °C. For 1 two not well resolved steps are observed, whereas 2 decomposes in one step. In the X-ray powder patterns of the grey products Sb2S3, Co/NiSbS and Co/NiS could be identified.
Databáze: OpenAIRE
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