A thiosemicarbazone ligand functionalized by a phosphine group: Reactivity toward coinage metal ions

The reactivity of the phosphino-thiosemicarbazone ligand 2-(2-(diphenylphosphino)benzylidene)-N- ethylthiosemicarbazone (HLPEt) toward M(I) halides (M = Cu, Ag, Au) was studied. The complexes obtained, with formulae [Cu(HLPEt)(2)]Br (1), [Cu(HLPEt)(2)]I center dot 2H(2)O (2), [Ag(HLPEt)(LPEt)]center dot 3H(2)O (3), [Au-2(HLPEt)(2)Cl]Cl center dot CH3OH (4) were satisfactorily characterized by elemental analysis, IR, ESI and H-1/P-31 NMR. Moreover, we have obtained the crystal structure of the ligand HLPEt and its sulfide oxidized form HLP(S) Et, which represents a new case of desulfurization process in thiosemicarbazone ligands. In addition, we present the crystal structure of the complexes 1 + H2O + 3MeOH and [Au-2(HLPEt)(4)Cl]Cl center dot 3CH(3)OH (5), together with their interesting crystal packing. The complex 5 is an interesting case of a pseudo-chloronium gold(I) complex. The ligand HLPEt and the complexes 3 and 4 display intense luminescence at room temperature.