The coordination chemistry of sulfonyl-substituted thioureas towards the d8 metal centres platinum(II), palladium(II), nickel(II) and gold(III)

[Display omitted] •Series of Pt(II), Pd(II), Ni(II) and Au(III) complexes of sulfonylthiourea ligands synthesised.•Ligand coordinates through sulfur, with the NSO2R nitrogen uncoordinated.•Palladium complexes of sulfonylthioureas degrade in solution to μ-sulfido aggregates. Reactions of the complexes cis-[PtCl2(PPh3)2], [PtCl2(dppp)] (dppp = Ph2P(CH2)3PPh2), [MCl2(dppe)] (dppe = Ph2P(CH2)2PPh2, M = Ni, Pd), [PdCl2(bipy)] (bipy = 2,2′-bipyridine) and [AuCl2(bp)] (bp = cyclometallated 2-benzylpyridine) with p-TolSO2NHC(S)NHPh and Et3N in refluxing methanol gave a series of new thiourea complexes containing the ligand bound as a dianion through the S and the NPh groups. The related thioureas RSO2NHC(S)NHPh (R = Me, Et) and p-TolSO2NHC(S)NHCH2CH=CH2 were also reacted with cis-[PtCl2(PPh3)2] to form the corresponding complexes [Pt{RSO2NC(S)NPh}(PPh3)2] and [Pt{TolSO2NC(S)NCH2CH=CH2}(PPh3)2] respectively. X-ray structure determinations were carried out on the thiourea MeSO2NHC(S)NHPh and its platinum complex [Pt{MeSO2NC(S)NPh}(PPh3)2], as well as [Pt{TolSO2NC(S)NPh}(PPh3)2]. Both complexes form the distal isomer with a remote NSO2R group, and no evidence was observed for isomerisation of these platinum complexes in solution. The palladium complexes [Pd{TolSO2NC(S)NPh}L2] [L2 = Ph2PCH2CH2PPh2 (dppe), or 2,2′-bipyridine (bipy)] undergo decomposition in solution to form the sulfide-bridged aggregates [Pd3S2(L2)3]2+, identified by ESI MS and 31P NMR.