Neutral Hexacoordinate Silicon(iv) Complexes with an <i>Si</i>SO₃NC Skeleton and a Neutral Pentacoordinate Silicon(iv) Complex Containing a Trianionic Tetradentate <i>O</i>,<i>N</i>,<i>O</i>,<i>O</i> Ligand

The neutral hexacoordinate silicon(iv) complexes 8−10 (SiSO3NC skeleton) were synthesized by replacement of the chloro ligand of the pentacoordinate chlorosilicon(iv) complex 5 by monoanionic bidentate O,O ligands of the acetylacetonato type. For that purpose, compound 5 was treated with compounds of the formula type R1C(O)−CHC(OSiMe3)R2 (R1 = R2 = Me; R1 = R2 = Ph; R1 = Me, R2 = Ph). In contrast, treatment of 5 with PhC(O)−CHC(OSiMe3)CF3 afforded the neutral pentacoordinate silicon(iv) complex 11·CH3CN (SiO3NC skeleton). The identities of 8−10 and 11·CH3CN were established by elemental analyses and solid-state and solution NMR experiments; additionally, the solvates 8·CH3CN, 9·CH3CN, 10·CH3CN, and 11·2CH3CN were studied by single-crystal X-ray diffraction.