Syntheses, Crystal Structures, and Photocatalytic Properties of a Series of Mercury Thioantimonates Directed by Transition Metal Complexes

With
different transition metal (TM) complexes as structure-directing
agents or structure-building units, a series of new mercury thioantimonates
with abundant architectures ranging from one-dimensional (1D) ribbons
to two-dimensional (2D) layers have been solvothermally synthesized
and structurally characterized. Compounds [Co­(en)3]­Hg2Sb2S6 (1) (en = ethylenediamine)
and [Ni­(1,2-dap)3]2­HgSb3S7Cl (2, 1,2-dap = 1,2-diaminopropane) contain
a discrete 2D [Hg2Sb2S6]n2n– layer and
1D [HgSb3S7]n3n– chain, respectively. Compounds
[Ni­(1,2-dap)3]­HgSb2S5 (3) and [Mn­(dien)2]­HgSb2S5 (4, dien = diethylenetriamine) feature distinct 2D
[HgSb2S5]n2n– layer and 1D [HgSb2S5]n2n– ribbon, respectively, whereas the 1D [HgSb2S5]n2n– chains are attached by [TM­(tren)]2+ complexes via TM–S
bonds to form 1D {[TM­(tren)]­HgSb2S5}n ribbons in compounds [TM­(tren)]­HgSb2S5 (TM = Mn (5), Fe (6), Co
(7), tren = tris­(2-aminoethyl)­amine). Compounds [TM­(dien)2]­Hg3Sb4S10 (TM = Mn (8), Co­(9), Ni­(10)) feature 2D [Hg3Sb4S10]n2n– anionic layers separated by
[TM­(dien)2]2+ cations. The most interesting
structural feature of these compounds is the presence of three different
types of coordination environments of Hg centers including linear
[HgS2] unit, [HgS3] triangle, and [HgS4] tetrahedron. The optical properties and thermal stabilities of
the title compounds were studied by UV–vis spectra and thernogravimetric
analyses, respectively. The photocatalytic experiments indicated that 3, 4, and 10 were able to degrade
rhodamine B (RhB) under visible irradiation.