Hexacoordinate Silicon(IV) Complexes Containing Thiocyanato‐N Ligands — Syntheses, Structural Characterization, and Computational Studies

The hexacoordinate silicon(IV) complexes [NEt4](2)-[Si(NCS)(6)] (2), [K(18-crown-6)](2)[Si(NCS)(6)].2CH(3)CN (3.2CH(3)CN), and cis-[(acac)(2)Si(NCS)(2)] (cis-4; acac = acetylacetonato-O,O) were synthesized, starting from Si(NCS)(4) (1). Compounds 1, 2, 3.2CH(3)CN, and cis-4 were structurally characterized in the solid state (C-13, N-15 (cis-4 only), and Si-29 MAS NMR; crystal structure analyses) and in solution (H-1, C-13, and Si-29 NMR; cis-4 only). The experimental investigations were complemented by computational studies (RI-MP2 geometry optimizations of 1, [Si(NCS)(6)](2-), cis-4, and trans-4; calculations of the Si-29 NMR chemical shifts using the optimized structures).