High-pressure synthesis and crystal structure of B2S3

Abstract Two new high-pressure phases of binary boron–sulfur compounds, B 2 S 3 -II and B 2 S 3 -III, were synthesized at 3–6.2 GPa. A single crystal of B 2 S 3 -III was grown and the structure was determined (tetragonal, space group I 4 1 /a, a =16.086(2) A, c =30.488(4) A; V =7888(1) A 3 , Z =100, R =3.0% and R w =2.8% for 3047 observed data [ I >3.00σ( I )]. The structure of B 2 S 3 -III consists of two kinds of macrotetrahedra built up from 20 and 34 BS 4 -tetrahedra. These macrotetrahedra connect each other to form an interpenetrating zincblende-type structure by sharing BS 4 -tetrahedra at the corners of those. B 2 S 3 -III is anticipated having a rather disordered structure. From the UV-Vis diffuse reflectance spectrum, the optical band gap of B 2 S 3 -III was estimated to be 3.7 eV.