Four new thioantimonate(III) compounds with the general formula [TM(tren)]Sb4S7, TM = Mn 1, Fe 2, Co 3 and Zn 4, were synthesized under solvothermal conditions by reacting elemental TM, Sb and S in an aqueous solution of tren (tren = tris(2‐aminoethyl)amine). All compounds crystallize in the monoclinic space group P21/n with four formula units in the unit cell. Single crystal X‐ray analyses of 1 [a = 8.008(2), b = 10.626(2), c = 25.991(5) Å, β = 90.71(3)°, V = 2211.4(8) Å3], 2 [a = 8.0030(2), b = 10.5619(2), c = 25.955(5) Å, β = 90.809(3)°, V = 2193.69(8) Å3], 3 [a = 7.962(2), b = 10.541(2), c = 25.897(5) Å, β = 90.90(3)°, V = 2173.0(8) Å3] and 4 [a = 7.978(2), b = 10.625(2), c = 25.901(5) Å, β = 90.75(3)°, V = 2195.2(8) Å3] reveal that the compounds are isostructural. The [Sb4S7]2‐ anions are composed of three SbS3 trigonal pyramids and one SbS4 unit as primary building units (PBU). The PBUs share common edges and corners to form semicubes (Sb3S4) which may be regarded as secondary building units (SBU). The SBUs and SbS3 pyramids are joined in an alternating fashion yielding the [Sb4S7‐] anionic chain which is directed along [100]. Weaker Sb‐S bonding interactions between neighbored chains lead to the formation of layers within the (001) plane which contain pockets that are occupied by the cations. The TM2+ ions are in a trigonal bipyramidal environment of four N atoms of the tren ligand and one S atom of the thioantimonate(III) anion. The optical band gaps depend on the TM2+ ion and amount to 3.11 eV for 1, 2.04 eV for 2, 2.45 eV for 3, and 2.60 eV for 4.
