N-H cleavage vs. Werner complex formation: reactivity of cationic Group 14 tetrelenes towards amines

β-Diketiminate ligands featuring backbone NMe2 groups have been exploited to access a series of two-coordinate cations of the type [(N-nacnac)E]+ (E = Si, Ge, Sn), whose reactivity towards N-H bonds has been investigated. While the heavier group 14 systems react via simple adduct formation, N-H oxidative addition occurs for E = Si, consistent with differences in EII/EIV redox potentials. The structurally characterized Ge/Sn adducts can be viewed as models for the corresponding (transient) Si systems [(N-nacnac)Si·(NH2R)]+ (R = H, tBu) - which are potential intermediates in the formation of [(N-nacnac)Si(H)(NHR)]+ via a proton-shuttling mechanism.