Synthesis and characterization of new, four-coordinate, high-spin iron(II) and manganese(II) complexes of the general form L 2MR 2 (L 2 = neutral chelating ligand, R = alkyl) are described. Alkylation of the α-diimine complex, [ArN=C(Me)-C(Me)=NAr]FeCl 2 (Ar = 2,6-diisopropylphenyl), as well as the enantiopure iron dichloride compounds, (-)-(sparteine)FeCl 2 and (S)-( tBuBox)FeCl 2 ((S)-( tBuBox) = 2,2-bis[2-[4(S)-(R′)-1,3-oxazolinyl]propane), with LiCH 2SiMe 3 afforded the corresponding dialkyl derivatives. Solution magnetic susceptibility measurements and X-ray diffraction studies reveal each of the new iron(II) bis-trimethylsilylmethyl complexes to be high-spin, S = 2, tetrahedral molecules. In addition (-)-(sparteine)Fe(CH 2CMe 3) 2, (-)-(sparteine)Fe(CH 2C 6H 5) 2, and (S)-( tBuBox)Fe(CH 2C 6H 5) 2 were also prepared and characterized by NMR spectroscopy and elemental analysis. An enantiopure, high-spin, tetrahedral manganese(II) dialkyl complex, (-)-(sparteine)Mn(CH 2SiMe 3) 2, has also been synthesized. The catalytic activity of the new iron complexes in carbon-carbon bond forming processes has been evaluated, and stoichiometric reactions of the dialkyls with olefins, carbon monoxide, and the Lewis acid B(C 6F 5) 3 have been examined.
All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry