Trialkylsilyl-substituted pentalene ligands

The reaction between [C8H6][Li(DME)](2) and chlorotrimethylsilane affords t he trimethylsilyl-substituted dihydropentalene C8H6(SiMe3-1,4)(2), which ma y be deprotonated with (BuLi)-Bu-n in dimethoxyethane to give [C8H4(SiMe3-1 ,4)(2)][Li(DME)](2); the latter reacts with chlorotrimethylsilane to give C 8H4(SiMe3-1,1',4,4')(4). Similarly, treatment of [C8H6][Li(DME)](2) with tr iisopropylsilyl triflate gives C8H6((SiPr3)-Pr-i-1,4)(2); deprotonation of the latter with KNH2 in, diethyl ether affords [C8H4((SiPr3)-Pr-i-1,4)2][K] (2), which has been crystallographically characterized and exhibits a chain structure in the solid state.