Heterobimetallic lithium alkyltriimido aluminate cages containing the [R'Al(NR)3]4- tetraanion (R' = Bu(n), Et; R = 2-OMeC6H4).
Attempted metallation of a triamidoaluminane gives a complex containing the [R'Al(NR)3]4- anion whose formal tetranegative charge is the highest charge observed crystallographically for a simple mononuclear imido main group anion system.