compounds of Pd(II) and Pt(II) with thiodiacetic acid [(H 2 L) 2 MX 2 ] [H 2 L = S(CH 2 COOH) 2 , M = Pd or Pt, X = C1 or Br] were synthesized. Independently of the reaction conditions (aqueous or non-aqueous media) the complexes produced had the same structure. The vibrational spectroscopic data suggested that in the square-planar complexes of Pd(II) and Pt(II) the thiodiacetic acid is coordinated