Solvothermal synthesis and characterization of thioindate–thioantimonates with transition-metal complexes: The first examples of the incorporation of transition metal ions into In–S–Sb frameworks

Abstract

Three new thioindate–thioantimonates [Ni(en)₃][In₂Sb₂S₇] (1, en = ethylenediamine), [(Ni(en)₃)]₃(en)[In₆Sb₆S₂₁] (2), and [Co(tren)InSbS₄] (3, tren = tris(2-aminoethyl)amine) have been solvothermally synthesized and structurally characterized. Compound 1 contains dimeric [In₂S₇] units built of two tetrahedral [InS₄] units sharing one corner and [SbS₃] trigonal-pyramids, which are interconnected to form a puckered [In₂Sb₂S₇]_n²ⁿ⁻ layer with 4-, 5- and 6-heterorings. [Ni(en)₃]²⁺ complex cations as structure-directing and charge-balancing agents are located at the interlayer spaces. Compound 2 consists of a 3-D polymeric [In₆Sb₆S₂₁]_n⁶ⁿ⁻ anion, [Ni(en)₃]²⁺ cations, free en molecule and a water molecule. The 3-D polymeric [In₆Sb₆S₂₁]_n⁶ⁿ⁻ anion is composed of [In₂Sb₂S₈]_n⁴ⁿ⁻ chains and heterometallic [In₂Sb₂S₉] clusters, which are interconnected to give 3-D frameworks with 10-ring helical channels, 14- and 20-ring channels. Compound 3 contains dimeric [In₂S₆] units constructed by two tetrahedral [InS₄] sharing a common edge and [SbS₃] trigonal-pyramids, which link to form a new [InSbS₄]_n²ⁿ⁻ layer with large 10-heterorings. Each [Co(tren)]²⁺ group is appended within the cavity of the 10-heteroring via one Co–S–Sb bond. 3 represents the first example of the incorporation of transition metal ions into a In–S–Sb framework. Density functional theory calculation for 3 also has been performed, and the optical properties of 1–3 have been characterized by UV-vis spectra.