Synthesis and Structural Characterization of Neutral Higher-Coordinate Silicon(iv) Complexes with Tridentate Dianionic Chelate Ligands

The neutral pentacoordinate silicon(iv) complexes 8 and 9 with an SiO2N3 skeleton and the neutral hexacoordinate silicon(iv) complex 10⋅ 1/2 CH3CN with an SiO4N2 skeleton were synthesized, starting from tetra(cyanato‐N)silane or tetra(thiocyanato‐N)silane. Compounds 8 and 9 contain one tridentate dianionic ligand derived from 4‐[(2‐hydroxyphenyl)amino]pent‐3‐en‐2‐one and two monodentate singly charged cyanato‐N or thiocyanato‐N ligands bound to the silicon(iv) coordination center, whereas the silicon(iv) center of 10 is coordinated by two of these tridentate dianionic ligands. All compounds were characterized by single‐crystal X‐ray diffraction and solid‐state and solution NMR spectroscopy. To get more information about the stereochemistry of the compounds studied, the experimental investigations were complemented by computational studies. Neutral higher‐coordinate silicon(iv) complexes (see structures) were synthesized, starting from tetra(cyanato‐N)‐ or tetra(thiocyanato‐N)silane, and were structurally characterized by single‐crystal X‐ray diffraction and solid‐state and solution NMR spectroscopy. The experimental investigations were complemented by computational studies.