A new modification of MnSb2S4 crystallizing in the HgBi2S4 structure type

A new modification of MnSb2S4 was synthesized by solid state reaction of Mn S, and Sb2S3 at 500 degrees C. The monoclinic, purple-red compound crystall izes in the HgBi2S4 structure type. Single crystal measurements provided th e space group C2/m (no. 12) with a = 12.747(3) Angstrom, b = 3.799(1) Angst rom, c = 15.106(3) Angstrom, beta = 113.91(3)degrees, V = 668.7(3) Angstrom (3), and Z = 4. The refinement converged to R = 0.0403, and wR2 = 0.1001 fo r 913 unique reflections and 46 parameters. The crystal structure of MnSb2S 4 (mC28) consists of strands of edge-sharing [MnS6] which are interlinked t o layers by distorted square pyramids [SbS5] (d(Sb-S) < 3.1 Angstrom). MnSb 2S4 (mC28) shows a greater distortion of the [Sb-S] polyhedra as compared t o the [Bi-S] polyhedra in analogous MnBi2S4. This is due to an enhanced ste reochemical influence of the lone electron pair of Sb3+. Raman spectra of M nSb2S4 (mC28) are dominated by nu(Sb-S) stretching modes at 300 cm(-1), and at 283 cm(-1), respectively.