Isolation and Reactivity of a Square-Planar Trisamido Silane

Square-planar coordination at tetravalent silicon is highly disfavored, rendering structurally authenticated Si(+IV) complexes of this type exceedingly rare. Herein, we report the synthesis and isolation of a square-planar silicon(+IV) hydride supported by an unsymmetric, trianionic N,N,N-pincer ligand with a dearomatised backbone. Single-crystal X-ray diffraction confirms a strictly planar, four-coordinate silicon centre, with spectroscopic data and quantum-chemical calculations providing complementary support for this bonding motif. Reactivity studies demonstrate element-ligand cooperative substrate activation driven by ligand rearomatisation, thereby paralleling constant-oxidation-state transformations in late transition metal systems and challenging the prevailing reliance on low-valent p-block species for bond activation.