Synthesis and characterization of potassium aryl- and alkyl-substituted silylchalcogenolate ligands

Treatment of either triphenyl(chloro)silane or tert-butyldiphenyl(chloro)silane with potassium metal in THF, followed by addition of 18-crown-6, affords [K(18-crown-6)][SiPh3] () and [K(18-crown-6)][SiPh2(t)Bu] (), respectively, as the reaction products in high yield. Compounds and were fully characterized including by multi-nuclear NMR, UV/vis and IR spectroscopies. Addition of elemental chalcogen to either or , results in facile chalcogen insertion into the potassium-silicon bond to afford the silylchalcogenolates, [K(18-crown-6)][E-SiPh2R] (E = S, R = Ph (); E = Se, R = Ph (); E = Te, R = Ph (); E = S, R = (t)Bu (); E = Se, R = (t)Bu (); E = Te, R = (t)Bu ()), in moderate to good yield. The silylchalcogenolates reported herein were characterized by multi-nuclear NMR, UV/vis and IR spectroscopies, and their solid-state molecular structures were determined by single-crystal X-ray crystallography. Importantly, the reported compounds crystallize as discrete monomers in the solid-state, a structural feature not previously observed in silylchalcogenolates, providing well-defined access routes into systematic metal complexation studies.