Preparation and characterization of rhenium(I) complexes with thiosemicarbazone ligands derived from resorcinol

New neutral tricarbonylrhenium(I) complexes with bidentate thiosemicarbazone ligands derived from resorcinol have been prepared. Ligands were obtained by condensation reactions of 2,4-dihydroxybenzaldehyde (dhb) and 2,4-dihydroxyacetophenone (dha) with thiosemicarbazide derivatives. The metal complexes have been characterized by elemental analysis, mass spectrometry, spectroscopic methods (IR, 1H NMR) and the crystal structures for eight of these compounds have been elucidated. The Re(I) metal centers are coordinated through the azomethine nitrogen and the sulfur atoms establishing five-membered chelate rings (κ-S,N(3)). The deprotonation of the ligand HL6 and the labilization of the halogen produces the formation of the dimeric complex [Re2(L6)2(CO)6] by Re–S–Re bridges, where S is the thiolate sulfur atom from a κ-S,N(3)-bidentate thiosemicarbazonate ligand.

Graphical abstractNew neutral tricarbonylrhenium(I) complexes with bidentate thiosemicarbazone ligands derived from resorcinol have been prepared. The Re(I) metal centers are coordinated through the azomethine nitrogen and the sulfur atoms establishing five-membered chelate rings (κ-S,N(3)). The deprotonation of the ligand HL6 produces the labilization of the halogen and the formation of the dimeric complex [Re2(L6)2(CO)6] by Re–S–Re bridges, where S is the thiolate sulfur atom from a κ-S,N(3)-bidentate thiosemicarbazonate ligand.Figure optionsDownload full-size imageDownload as PowerPoint slide