A new modification of MnSb2S4 crystallizing in the HgBi2S4 structure type

Abstract

A new modification of MnSb2S4 was synthesized by solid state reaction of MnS, and Sb2S3 at 500 °C. The monoclinic, purple-red compound crystallizes in the HgBi2S4 structure type. Single crystal measurements provided the space group C2/m (no. 12) with a = 12.747(3) Å, b = 3.799(1) Å, c = 15.106(3) Å, β = 113.91(3)°, V = 668.7(3) Å3, and Z = 4. The refinement converged to R = 0.0403, and wR = 0.1001 for 913 unique reflections and 46 parameters. The crystal structure of MnSb2S4 (mC28) consists of strands of edge-sharing octahedra [MnS6] which are interlinked to layers by distorted square pyramids [SbS5] (d(Sb-S) < 3.1 Å). MnSb2S4(mC28) shows a greater distortion of the [Sb-S] polyhedra as compared to the [Bi-S] polyhedra in analogous MnBi2S4. This is due to an enhanced stereochemical influence of the lone electron pair of Sb3+. Raman spectra of MnSb2S4 (mC28) are dominated by ν Sb-S stretching modes at 300 cm-1, and at 283 cm-1, respectively.