An Antimony Sulfide with Copper Pillars:  [C₄H₁₂N₂]_0.5[CuSb₆S₁₀]

Abstract

A new copper−antimony sulfide, [C 4 H 12 N 2 ] 0.5 [CuSb 6 S 10 ], has been hydrothermally synthesized from binary metal sulfides in the presence of triethylenetetramine and characterized by single-crystal X-ray diffraction, thermogravimetry, elemental analysis, and SQUID magnetometry. The product ( M r = 1158.72) crystallizes in the monoclinic space group P 2 1 / n with a = 11.2578(4) Å, b = 12.5259(5) Å, c = 13.9390(7) Å, β = 102.445(3)°, and V = 1919.4 Å 3 . The structure consists of cyclic Sb 3 S 6 3 - units in a boatlike conformation, linked by Sb−S bonds to form a complex Sb 6 S 12 6 - building block. Sb−S bonds serve to link Sb 6 S 12 6 - units to four others in a herringbone array, forming a sheet of stoichiometry Sb 6 S 10 2 -, containing 24-membered rings of alternating Sb and S atoms. Pairs of edge-sharing CuS 4 distorted tetrahedra form pillars which link Sb 6 S 10 2 - layers together. The interlayer space contains piperazine cations, formed by cyclization of the triethylenetetramine during synthesis. Bond-valence sums are consistent with the presence of antimony(III) and copper(I), requiring complete protonation of the amine.