Abstract Various homogeneous metalate(O) complexes are synthesized with [SnCl3] -as a ligand. Complexes of the type [M(SnCl3)6]6- are prepared from [M(CO)3(SnCl3)3]3-(M = Cr, Mo, W) in nitromethane. [Fe(SnCl3)5]5- is formed by UV irradiation of [Fe(CO)4SnCl3]- in aceto-nitrile. [M(SnCl3)4]4-(M = Ni, Pd, Pt) anions are synthesized by thermal substitution reactions with Ni(CO)4, Pd(PF3)4, and Pt(PF3)4. All metalate(O) ions are isolated as salts with the [N(C2H5)4]+ cation and characterized by IR spectra and 119mSn-Mössbauer spectra as well as by analysis.