(C6N2H18)Sb4S7 a Thioantimonate(III) with a Layered [Sb4S7]2– Anion in the Presence of a Diprotonated Amine as Structure Director

Abstract

The new thioantimonate(III) (C6N2H18)Sb4S7 (C6N2H16 = 1,6-diaminohexane) was synthesized under solvothermal conditions using Sb, S and 1,6-diaminohexane (1,6-DAH). The compound crystallizes as orange needles in the triclinic space group P1̅ with lattice parameters a = 6.9834(5), b = 11.8748(10), c = 13.6588(12) Å , α = 115.248(9), β = 100.165(9) and γ = 92.568(9)°. A central SbS4 group shares edges with two other SbS4 moieties forming Sb3S8 units which are joined by SbS3 pyramids sharing vertices to form a chain of alternating Sb3S8 and SbS3 units. One S atom of the SbS3 pyramid connects neighboring chains into sheets which contain large Sb10S10 heterorings. The sheets are then further connected into four atoms thick double sheets. Six edge-linked SbS4 units are condensed yielding a complex Sb6S14 building block. Layers of diprotonated amines and thioantimonate( III) layers are stacked along [001] in a sandwich-like fashion with an interlayer distance of 8.46 Å . The amine layer is two molecules thick with the amines being oriented parallel to the anionic layers. The title compound represents the first example for a layered [Sb4S7]2− anion with a diamine as structure director. The compound is an optical semiconductor with a band-gap of about 1.9 eV