Hexacoordinated M^IV (M=Ti, Zr, Hf) Tetrachlorido Complexes with Chelating Dithienylethane Based 1,2 Diketone Ligand - -Conjugation as Decisive Factor for Axial Chirality Mode

1,2-bis(2,5-dimethylthiophen-3-yl)ethane-1,2-dione (1, DTEthane) reacts with MCl4 metal precursors of group four (M=Ti, Zr, Hf) via coordination of the carbonyl groups. The molecular structure of complex 2-4 were determined in scXRD studies in the solid state and characterized by means of multi-nuclear and multi-dimensional NMR spectroscopy in solution. While the resulting titanium complex [TiCl4(DTEthane)] 2 shows a monomeric structure, where 1 binds in a bidentate fashion, complexes with a Zr (3) and Hf (4) center have dimeric scaffolds in which the ligands adopt a bridging mode. Quantum chemical calculations using density functional theory (G16, B97D3/def2-TZVP) were used to evaluate the general trend of dimer formation (Ti更多