We report the preparation and characterization of two new polyoxothiometalate species, {Mo16} = {(Mo2O2S2)8(OH)16(C4O4)2}(4-) (compound 1) and {Mo12} = {(Mo2O2S2)6(OH)12(CH3COO)2}(2-) (compound 2). Control of synthesis is achieved by the addition of the organic-template and further re-arrangement is controlled simply by the addition of potassium to a precursor compound yielding compound 2. The structures of the compounds are discussed and we also show that ion-mobility mass spectrometry can be used to resolve the species and their building blocks in solution.