The tridentate ligand precursors R′P(CH₂SiMe₂NR′′)₂ (^R′R′′[NPN]: R′ = Cy, Ph; R′′ = Ph, Mes, Me) were prepared from metathesis reactions of a lithiated amine, chloro(chloromethyl)dimethylsilane, the appropriate 1° phosphine, and n-butyl lithium and were isolated as solvent adducts. Metathesis between ^CyPh[NPN]Li₂(OEt₂), 2, and VCl₃(THF)₃ afforded (^CyPh[NPN]VCl)₂, 7, whose solid-state structure was established by X-ray crystallography. Reduction attempts of the (^R′R′′[NPN]VCl)₂ species with KC₈ incorporated molecular nitrogen but were complicated by imide formation and ligand decomposition. Metathesis of 2 with NbCl₂Me₃ afforded the highly unstable complex ^CyPh[NPN]NbMe₃, 15. Attempts to hydrogenate this species were unsuccessful.Key words: vanadium, niobium, metathesis, coordination chemistry, reduction, hydrogenation.