Alkali Metal Carbatrane Compounds [Tism^PrⁱBenz]M: Synthesis and Structural Characterization of a Complete Series of Monomeric Alkali Metal Alkyl Compounds

The tris[(1-isopropylbenzimidazol-2-yl)dimethylsilyl]methyl thallium compound, [Tism^PrⁱBenz]Tl, reacts with Li, Na, K, and Rb to afford the respective alkali metal carbatrane complex, [Tism^PrⁱBenz]M (M = Li, Na, K, and Rb), while the cesium complex [Tism^PrⁱBenz]Cs is obtained via the reaction of [Tism^PrⁱBenz]Li with CsF. These carbatrane compounds [Tism^PrⁱBenz]M (M = Li, Na, K, Rb, and Cs) constitute the first complete series of structurally characterized monomeric alkyl compounds of the nonradioactive alkali metals.