Palladium and platinum pyrimidine-2-thionate complexes with diphosphines

[MCl2(P–P)] (M = Pd and Pt; P–P = dppe and dppm) reacts with NaC4H3SN2, in a 1:2 molar ratio at room temperature, to give [M(S-C4H3SN2)2(dppe)] [M = Pd (1); M = Pt, (2)], [Pd(S-C4H3SN2)2(dppm)2] (3) and trans-[Pt(S-C4H3SN2)2(dppm)] (5), as well as other by-products such as [Pd2(S,N-C4H3SN2)4] (4) and trans-[Pt(S-C4H3SN2)2(PPh2Me)2] (6). A possible mechanism for the formation of 6, which requires cleavage of P–C bonds of the dppm ligands, is proposed.

[MCl2(P–P)] (M = Pd and Pt; P–P = dppe) reacts with pyrimidine-2-thionate NaC4H3SN2, in a 1:2 molar, to give [M(S-C4H3SN2)2(dppe)] although with P–P = dppm and depending on the metal, Pt or Pd different complexes are obtained as represented on the scheme, including the formation of PPh2Me complex from dppm derivative.Figure optionsDownload as PowerPoint slideHighlights
► Synthesis and X-ray structure of dppm and dppe complexes of palladium, platinum with pyrimidine-2-thionate.
► Formation of of PPh2Me complex from dppm derivatives which requires the cleavage of P–C bond.
► A plausible mechanism for the P–C cleavage is proposed.