Synthesis and structure of the silylated benzene radical anion salts [K([18]crown-6){C6H4(SiMe3)2-1,4}] and [K([18]crown-6)(THF)2][C6H2(SiMe3)4-1,2,4,5]

摘要: Abstract The crystalline compound [K([18]crown-6){C6H4(SiMe3)2-1,4}] (1) was prepared by the low-temperature reduction of para-disilylated benzene with K/[18]crown-6 in toluene followed recrystallisation from same solvent. Reduction 1,2,4,5-tetrasilylated 2(K/[18]crown-6) produced a hydrocarbon-insoluble powder identified as dianionic derivative [K([18]crown-6)]2[C6H2(SiMe3)4-1,2,4,5)] (2), which upon crystallisation THF/Et2O yielded [K([18]crown-6)(THF)2][C6H2(SiMe3)4-1,2,4,5] (3). An X-ray diffraction study revealed that 1 comprised contact ion pair crown-encapsulated K cation η5-connected to planar ring substituted radical anion, while 3 contained well separated and anion.