Directing the structures of silver-antimony sulphides: A new topological variant of the [Ag5Sb3S8] double layer

A new silver-antimony sulphide, C₆H₂₀N₄]Ag₅Sb₃S₈], has been synthesised solvothermally in the presence of triethylenetetramine and characterised by single-crystal X-ray diffraction, thermogravimetry and elemental analysis. The compound crystallises in the space group P2₁/m (a=6.2778(7), b=15.8175(16) and and β=104.561(5)°) and adopts a structure in which honeycomb-like sheets of fused six-membered silver-antimony-sulphide rings are linked through Ag-S bonds to form double layers. The idealised structure can be considered to be derived from that of antifluorite and represents a second structure type for the Ag₅Sb₃S₈]²⁻ double layer.