Solvothermal syntheses, crystal structures, and properties of new mercury(II)–thioantimonates(III) and a mixed-valent thioantimonate(III,V)

New heterometallic thioantimonates(III) [Co(dien)2]HgSb2S5 (1), [Ni(dien)2]HgSb2S5 (2) and [H2dien]HgSb8S14 (3), and a mixed-valent thioantimonate(III,V) [Co(dien)2]2Sb4S9 (4) were solvothermally prepared in diethylenetriamine (dien) solvent from Co(Ni)–Hg–Sb–S, Hg–Sb–S and Co–Sb–S systems, respectively. In 1 and 2, the bimeric subunit Sb2S5 condenses with HgS4 tetrahedron via sharing common S atoms to form an one-dimensional [HgSb2S5]n2n− chain, in which a new μ3-1κ2S1,S5:2κS2:3κS4 bridging mode of the Sb2S5 subunit is obtained. In 3, four SbS3 trigonal pyramids and a linear HgS2 unit condense via sharing S atoms to generate an one-dimensional double-lined [HgSb8S14] n2n− chain. In 4, three SbIIIS3 pyramids and a SbVS4 tetrahedron share common corners to form an one-dimensional mixed-valent [Sb4S9]n4n− anion. The syntheses of 1–4 demonstrated that the Hg2+ ion is easily incorporated into thioantimonate networks, and has a higher affinity to S than that of transition metals. 1–4 exhibit semiconducting properties with optical band gaps in 2.0–2.4 eV.

Graphical abstarctMercury thioantimonates(III) and thioantimonate(III,V) were solvothermally prepared, and a new coordination mode for the Sb2S5 subunit are observed in the mercury thioantimonates(III). Figure optionsDownload as PowerPoint slideHighlights
► Mercury(II)–thioantimonates(III) [Co(dien)2]HgSb2S5, [Ni(dien)2]HgSb2S5 and [H2dien]HgSb8S14 and a a mixed-valent thioantimonate(III,V) [Co(dien)2]2Sb4S9 were solvothermally prepared.
► A new μ3-1κ2S1,S5:2κS2:3κS4 bridging coordination mode of the Sb2S5 subunit is obtained.
► The mercury(II)–thioantimonates(III) are semiconducting materials with band gaps in 2.04–2.25 eV.