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)](2)HgSb3S7Cl (2, 1,2-dap = 1,2-diaminopropane) contain a discrete 2D [Hg2Sb2S6](n)(2n-) layer and 1D [HgSb3S7](n)(3n-) chain, respectively. Compounds [Ni(1,2-dap)(3)]HgSb2S5(3)and[Mn(dien)(2)]HgSb2S5 (4, dien = diethylenetriamine) feature distinct 2D [HgSb2S5](n)(2n-) layer and 1D [HgSb2S5](n)(2n-) ribbon, respectively, whereas the 1D [HgSb2S5](n)(2n-) chains are attached by [TM(tren)](2+) complexes via TM-S bonds to form 1D {[TM(tren)]HgSb2S5}(n) ribbons in compounds [TM(tren)]center dot HgSb2S5 (TM = Mn (5), Fe (6), Co (7), tren = tris(2-aminoethyl)amine). Compounds [TM(dien)(2)]Hg3Sb4Si10 (TM = Mn (8), Co(9), Ni(10)) feature 2D [Hg3Sb4S10](n)(2n-) 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.