Activation of sulfur dioxide by bis[N,N'-diisopropylbenzamidinato(-)]silicon(II): synthesis of neutral six-coordinate silicon(IV) complexes with chelating O,O'-Sulfito or O,O'-dithionito ligands.

The neutral six-coordinate silicon(IV) complexes 2 and 3 (mixture of cis-3 and trans-3) were synthesized by reaction of the donor-stabilized silylene bis[N,N'-diisopropylbenzamidinato(-)]silicon(II) (1) with SO2 . Compounds 2 and 3 are the first silicon(IV) complexes with chelating sulfito or dithionito ligands, and 3 is even the first molecular compound with a chelating dithionito ligand. Compounds 2 and 3 were structurally characterized by crystal structure analyses and multinuclear NMR spectroscopic studies in the solid state and in solution.