[TM(en)3][SnSb4S9] (TM = Ni, Co): 3D Chiral Framework of Mixed Main-Group Metals and [Mn(dien)2]2Sb4S9: 1D Chains with Mixed-Valent Sb Centers

Two new isostructural quaternary tin(IV) antimony(III) sulfides, [TM(en)(3)][SnSb4S9] [TM = Ni (1), Co (2); en = ethylenediamine], and one mixed-valent thioantimonate (III and V), [Mn(dien)(2)](2)Sb4S9 (3, dien = diethylenetriamine),. have been solvothermally synthesized and structurally characterized. In the structures of 1 and 2, four neighboring SbS3 trigonal pyramids are condensed via corner-sharing to form bow-like Sb4S9 tetramers, which are further interconnected by SnS6 octahedra into the three-dimensional (3D) chiral [SnSb4S9](2-) framework with two types of one-dimensional (ID) chiral channels along the c axis. Compound 3 features a 3D network composed of ID anionic [Sb4S9](4-) chains and [Mn(dien)(2)](2+) complexes interconnected via various hydrogen bonds. The most interesting structural feature of 3 is the presence of two different oxidation states of antimony centers in the ID [Sb4S9](4-) chain with three different types of coordination environments, respectively. The optical absorption spectra indicate that the band gaps of compounds 1, 2, and 3 are 2.07, 2.04, and 2.29 eV, respectively. The thermal stabilities and magnetic properties of the title compounds are also studied.