层状MAgTeS_3(M=K,Rb)的溶剂热合成与表征

Solvothermal Synthesis and Characterization of MAgTeS_3 (M=K, Rb) with Layered Structure

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,P2_1/c,a=0.73639(6)nm,b=1.06468(8)nm,c=0.85203(6)nm,β=106.4640(10)°,V=0.64062(8)nm^3,Z=4,R(F)=4.44%,wR(F^2)=11.66%.2的结晶学数据:M_r=417.12,P2_1/c,a=0.75531(12)nm,b=1.07076(7)nm,c=0.8583(2)nm,β=106.497(6)°,V=0.66558(19)nm^3,Z=4,R(F)=6.00%,wR(F^2)=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.

Two thio-tellurite KAgTeS3 （1） and RbAgTeS3 （2） were synthesized solvothermally and characterized by X-ray single crystal diffraction. These isostructural compounds compose of infmite parallel chains formed by AgS4 tetrahedra sharing their vertices, and these chains are further connected by trigonalpyramidally coordinated Te^4＋ to form anionic layered structure with cations located between the layers. Crystal data for 1： Mr=370.75, P2 1/c, a =0.73639（6） nm, b= 1.06468（8） nm, c=0.85203（6） nm, β= 106.4640（10）°, V=0.64062（8） nm^3, Z=4, Mo Kα, λ=0.071073 nm, R（F）=4.44%, wR（F^2）= 11.66%. Crystal data for 2： Mr=417.12, P2 1/c, a=0.75531（12） nm, b= 1.07076（7） nm, c=0.8583（2） nm, β= 106.497（6）°, V= 0.66558（19） nm^3, Z=4, Mo Kα, λ=0.071073 nm, R（F）=6.00%, wR（F^2）= 15.43%. UV-Vis diffusion 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. Keywords solvothermal synthesis; quaternary thio-tellurite; crystal structure