Changing the Reactivity of Zero‐ and Mono‐Valent Germanium with a Redox Non‐Innocent Bis(silylenyl)carborane Ligand

Using the chelating C,C′‐bis(silylenyl)‐ortho‐dicarborane ligand, 1,2‐(RSi)(2)‐1,2‐C(2)B(10)H(10) [R=PhC(NtBu)(2)], leads to the monoatomic zero‐valent Ge complex (“germylone”) 3. The redox non‐innocent character of the carborane scaffold has a drastic influence on the reactivity of 3 towards reductants and oxidants. Reduction of 3 with one molar equivalent of potassium naphthalenide (KC(10)H(8)) causes facile oxidation of Ge(0) to Ge(I) along with a two‐electron reduction of the C(2)B(10) cluster core and subsequent Ge(I)‐Ge(I) coupling to form the dianionic bis(silylene)‐supported Ge(2) complex 4. In contrast, oxidation of 3 with one molar equivalent of [Cp(2)Fe][B{C(6)H(3)(CF(3))(2)}(4)] as a one‐electron oxidant furnishes the dicationic bis(silylene)‐supported Ge(2) complex 5. The Ge(0) atom in 3 acts as donor towards GeCl(2) to form the trinuclear mixed‐valent Ge(0)→Ge(II)←Ge(0) complex 6, from which dechlorination with KC(10)H(8) affords the neutral Ge(2) complex 7 as a diradical species.