The thiosulfate (S2O32- ) ion; a neglected but simple hetero-donor ligand towards platinum(II), palladium(II) and nickel(II)

Reactions of the thiosulfate ligand (as sodium thiosulfate, Na2S2O3.5H2O) with phosphine complexes of the group 10 metals Ni(II), Pd(II) and Pt(II) resulted in five neutral thiosulfate complexes, [Ni(S2O3)(dppe)] (dppe = Ph2PCH2CH2PPh2), [Pd(S2O3)(dppe)], [Pd(S2O3)(dppf)] (dppf = Fe(C5H4PPh2)(2)), [Pd(S2O3)(PPh3)(2)] and [Pt (S2O3)(PPh3)(2)]. X-ray structure determinations of [Pd(S2O3)(dppf)], [Pd(S2O3)(PPh3)(2)] and [Pt(S2O3)(PPh3)(2)] confirmed that thiosulfate ligand coordinates as a bidentate chelating ligand via both sulfur and oxygen donor atoms. In addition, reactions of the thiosulfate ligand with dinuclear chloride-bridged cyclopalladated complexes gave four mononuclear anionic complexes [Pd(S2O3)(damp)]- (damp = N,N-dimethylbenzylamino, (CH3)(2)NCH2C6H4), [Pd(S2O3)(ptpy)]-(ptpy = p-tolylpyridyl), ]Pd(S2O3)(bzpy)]- (bzpy = 2-benzylpyridyl) and [Pd(S2O3))pap)]- (pap = 2-(phenylazo)phenyl). The structure of (Ph3PCH2Ph)[Pd(S2O3)(pap)] by X-ray crystallography revealed the ability of thiosulfate ligand to cleave the bridging chloride ligand on the starting complexes by acting as an S,O-donor chelating ligand. An ESI mass spectrometric investigation showed that the coordinated thiosulfate ligand undergoes fragmentation at elevated capillary exit voltages.

Automated summary

This study investigates the reactions between the thiosulfate ligand and phosphine complexes of group 10 metals Ni(II), Pd(II), and Pt(II). The results reveal that the thiosulfate ligand can coordinate with the metals through both sulfur and oxygen donor atoms. Additionally, the ligand is capable of cleaving bridging chloride ligands in dinuclear complexes to form mononuclear anionic complexes.