SYNTHESIS, CHARACTERIZATION AND REACTIVITY OF BIS (BENZENE-1,2-DIOLATO)ISOTHIOCYANATO SILICON (IV) COMPOUNDS

Abstract

Some spirobicyclic anionic siliconates with isothiocyanate group linked to silicon atom, i.e. [(C₆H₄O₂)₂ Si NCS]⁻M⁺ [M = K (1), Na (2), K(18-crown-6) (3), NH₄ (4)] are prepared from the reactions of triethoxyisothiocyanato silane and benzene-1,2-diol in presence of the corresponding alkali metal/ammonium thiocyanates. The reaction of 1–4 with diethylamine results in the formation of intermolecular coordination complexes containing hexacoordinate siliconate anion, [(C₆H₄O₂),SiNCS.Et₂NH]⁻M⁺ [M = K (5), Na (6), K(18-crown-6) (7), Et₂NH₂ (8)]. The reactions of 1–3 with dimethylsulfite afford new pentaoxy siliconate derivatives, [(C₆H₄O₂)₂SiOMe]⁻M⁺(solv).[M(solv) = K(Me₂SO₃) (9), Na(Me₂SO₃) (10), K(18-crown-6) (11)]. All the compounds isolated here are characterized by elemental analyses, IR, multinuclei (¹H, ¹³C and ²⁹Si) NMR and FAB-mass spectroscopy.

Key Words:

• Anionic siliconates
• thiocyanate
• dimethylsulfite
• reactivity