Dithiolane and 1,4,7-Trithianonane Complexes of BiI3/CuI and SbI3/CuI

Reaction of BiI 3 /CuI or SbI 3 /CuI mixtures with the cyclic thioalkanes 1,3-dithiolane (DTL) or 1,4,7-trithiacyclononane (9S3) in toluene yielded the compounds BiCu 3 I 6 (DTL) 3 ( 1 ), SbCu 3 I 6 (DTL) 3 ( 2 ), and Bi 2 Cu 3 I 9 (9S3) 4 ( 3 ). All compounds were characterized via single crystal X-ray structure determination, powder X-ray diffraction, thermogravimetric analysis, elemental analysis, infrared, and diffuse reflectance spectroscopy. In all cases, sulfur centers bond only to Cu(I). Compounds 1 and 2 consist of isostructural 1D linear chain networks consisting of EI 6 octahedra (E = Bi, Sb) in which three mutually cis edges are capped with Cu(I) centers via μ 2 -I forming an ECu 3 I 6 cluster. All three DTL ligands are bidentate. Two DTL ligands bridge pairs of adjacent copper atoms in the ECu 3 I 6 cluster. Bridging by the remaining DTL links the clusters into infinite chains, …[ECu 3 I 6 (DTL) 2 ](DTL)… Compound 3 displays a unique ionic structure, [Cu 5 (9S3) 7 ] 5+ [Bi 4 CuI 18 (9S3)] 5− . The cation is composed of a central 9S3 ligand that bridges disordered duos/trios of [Cu(9S3)] + units, yielding [Cu 2.5 (9S3) 3.5 ] 2.5+ . The anion consists of half-independent face-sharing double octahedron, [Bi 2 I 9 ] 3− in which one of the trio of μ 2 -I centers further coordinates a half [Cu(9S3)] + unit, yielding [Bi 2 Cu 0.5 I 9 (9S3) 0.5 ] 2.5− . Hirshfeld analysis of 1 and 2 shows inter-chain contacts are dominated by I … I, H … I, S … H, and S … I interactions. The compounds show bandgaps in the range of 2.0–2.3 eV and thermally decompose sequentially with the loss of thioalkane, EI 3 , then CuI.