First paramagnetic Pd(II) complex with a PdN4S2 coordination core.

Reaction of the potassium salt of N-thiophosphorylated thiourea 2-PyNHC(S)NHP(S)(OiPr)(2) (HL) with PdCl(2) in aqueous MeOH leads to the formation of two mononuclear homoleptic complexes [Pd{2-PyNHC(S)NP(S)(OiPr)(2)-1,5-S,S'}(2)] ([Pd(L-1,5-S,S')(2)]) and [Pd{2-PyNHC(S)NP(S)(OiPr)(2)-1,5,7-N,N',S}(2)] ([Pd(L-1,5,7-N,N',S)(2)]), while the mechanically induced solid-state reaction of KL and PdCl(2) leads to the exclusive formation of [Pd(L-1,5,7-N,N',S)(2)]. The dithiocoordinated desmotrope is square-planar and diamagnetic, while the second desmotrope is unprecedentedly octahedrally configured and paramagnetic.