Crystal structure of piperidinium hexathiotetra-arsenate

Crystals of [C5H12N]+2[As4S6]2– are orthorhombic, space group Imm2, with a= 10·25, b= 19·61, c= 5·97 Å, Z= 2. The anion possesses a 'basket' structure in which the four arsenic atoms, and two of the sulphur atoms, lie on crystallographic mirror planes; the bond lengths are: As–As 2·579(12), As–S(terminal) 2·183(10), As–S(bridge) 2·302(11) and 2·231(8)Å. The As4S62– anions are linked by double zig-zag chains of S ⋯ H–N hydrogen bonds parallel to the z axis. The structure was refined to R 0·129 for 660 independent reflections.