层状MAgTeS3 (M＝K, Rb)的溶剂热合成与表征

以硫醇为螯合剂, 在溶剂热条件下合成了两种层状硫代亚碲酸盐KAgTeS₃ (1)和RbAgTeS₃ (2). X射线单晶解析表明, 1和2是类质同晶化合物. 在晶体结构中, 银硫四面体通过共用顶点形成无限的平行链, 在相邻链中银硫四面体取向相反, 这些链与链由三角锥配位的碲互相连接形成阴离子层状结构, 阳离子在阴离子层间. 1的结晶学数据为: M_r＝370.75, P2₁/c, a＝0.73639(6) nm, b＝1.06468(8) nm, c＝0.85203(6) nm, β＝106.4640(10)°, V＝0.64062(8) nm³, Z＝4, R(F)＝4.44%, wR(F²)＝11.66%. 2的结晶学数据: M_r＝417.12, P2₁/c, a＝0.75531(12) nm, b＝1.07076(7) nm, c＝0.8583(2) nm, β＝106.497(6)°, V＝0.66558(19) nm³, Z＝4, R(F)＝6.00%, wR(F²)＝15.43%. DSC及紫外-可见漫反射光谱研究表明, 这两种化合物为半导体, 并具有很好的热稳定性.

Solvothermal Synthesis and Characterization of MAgTeS3 (M=K, Rb) with Layered Structure

Two thio-tellurite KAgTeS₃ (1) and RbAgTeS₃ (2) were synthesized solvother-mally and characterized by X-ray single crystal diffraction. These isostructural compounds compose of infinite parallel chains formed by AgS₄ tetrahedra sharing their vertices, and these chains are further connected by trigonal-pyramidally coordinated Te^4＋ to form anionic layered structure with cations located between the layers. Crystal data for 1: M_r＝370.75, P2₁/c, a＝0.73639(6) nm, b＝1.06468(8) nm, c＝0.85203(6) nm, β＝106.4640(10)°, V＝0.64062(8) nm³, Z＝4, Mo Kα, λ＝0.071073 nm, R(F)＝4.44%, wR(F²)＝11.66%. Crystal data for 2: M_r＝417.12, P2₁/c, a＝0.75531(12) nm, b＝1.07076(7) nm, c＝0.8583(2) nm, β＝106.497(6)°, V＝0.66558(19) nm³, Z＝4, Mo Kα, λ＝0.071073 nm, R(F)＝6.00%, wR(F²)＝15.43%. UV-Vis diffu-sion reflectance spectra suggest that the crystals 1 and 2 are semiconductor with estimated band gaps 2.03 and 2.10 eV, respectively. The DSC data show that crystal 1 and crystal 2 collapse at 333 and 352 ℃ respectively, in nitrogen.