Half-sandwich titanium complexes with β-oxodithioester ligands

• Half-sandwich titanium complexes with β-oxodithioester ligands.
• Formation of C and A enantiomers.
• Crystal structure determination of pentacoordinated titanium complexes.

The reaction of CpTiCl3 with HLx [HLx = methyl 3-(4′-X-phenyl)-3-hydroxy-2-propenedithioate ligands; X = H(1), Me(2), OMe(3), Cl(4), Br(5)] in the presence of NEt3 yielded the corresponding half-sandwich complexes TiCpCl2(Lx) [X = H(6), Me(7), OMe(8), Cl(9), Br(10)]. Compounds 1–10 were characterized by elemental analyses, infrared, 1H and 13C NMR spectroscopy and EI mass spectrometry, while ligands 1,3–5 and complexes 6–10 were also characterized by single-crystal X-ray diffraction studies. The structural arrangements observed in 1,3–5 include an intramolecular O–H⋯S hydrogen bond. The metal center in 6–10 exhibits a square pyramidal geometry by means of the O∩S coordination mode of ligands, which led to the racemic form of the A, C enantiomers, associated by an inversion center.

Half-sandwich titanium complexes CpTiCl2Lx (Lx = methyl 3-(4′-X-phenyl)-3-hydroxy-2-propenedithioate) were prepared and characterized by analytical and spectroscopic methods. The solid-state structures of these compounds exhibit a titanium atom with a square pyramidal geometry through a ligand O∩S coordination mode, leading to the racemic form of the C, A enantiomers.Figure optionsDownload as PowerPoint slide