Reaction of CH₂(SiMe₃)P(Ph)₂NSiMe₃ (HLL′) I with LiBuⁿ afforded, after recrystallisation from diethyl ether, [Li{CH(SiMe₃)P(Ph)₂NSiMe₃}(OEt₂)₂]. Removal of the co-ordinating Et₂O molecules in vacuo and subsequent recrystallisation from hexane yielded the solvent-free dimeric lithium complex [Li{CH(SiMe₃)P(Ph)₂NSiMe₃}]₂. The crystal structures of the crystalline compounds [Li(LL′)(OEt₂)₂] and the fused dinuclear [Li(LL′)]₂ are reported. Each contains a planar Li(LL′) ring. The Li(2)–N bond of the Li(LL′) moiety of the latter is also part of a six-membered Li(2)–N–Li(1)–N–P–C ring, planar except for Li(2); the two Li atoms are bridged by a second [LL′]^– ligand, so that the bridgehead lithium atom Li(2) is bound to the allyl carbon of each [LL′]^– ligand, whereas Li(1) is bound to two nitrogen atoms. In toluene-d₈, this compound shows singlet ⁷Li-{¹H} and ³¹P-{¹H} NMR spectral signals, even at low temperatures. Its reaction with Me₃SiO₃SCF₃ afforded the phosphinimine CH(SiMe₃)₂P(Ph)₂ NSiMe₃ (HLL″) II, a potential precursor for a new 1-aza-2-phospha(V)allyl ligand, as was shown by its straightforward lithiation to yield Li(LL″). The novel phosphinimine CH₂{SiMe₂(NEt₂)}P(Ph)₂NSiMe₃ (HLL‴) III was synthesized by reaction of Li[CH₂P(Ph)₂NSiMe₃] with Et₂NSi(Me)₂Cl and, similar to the lithiation of II, reaction of III with LiBuⁿ afforded Li(LL‴) in high yield.