The first triazatrimethylenemethane dianion: crystal structure of dilithio-triphenylguanidine Li2[C(NPh)3] as its tetrahydrofuran solvate

The dilithiation of N,N′,N″-triphenylguanidine with n-butyllithium in tetrahydrofuran provides the first example of a triazatrimethylenemethane system [C(NPh)3]2–, isoelectronic with both [C(CH2)3]2– and [CO3]2–; the X-ray crystal structure of the dilithium salt shows it to exist as a dimer with planar CN3 structural units.