NMR spectroscopic studies have been performed on the mixed complexes formed by the lithium salt of acetonitrile (LiCH2CN) and the chiral lithium amides Li-(S)-N-(2-methoxybenzyl)-1-amino-1-phenyl-2-ethoxyethane (Li-1) and Li-(S)-N-isopropyl-2-amino-1-phenyl-3-methoxypropane (Li-2) in diethyl ether and tetrahydrofuran solvent. In diethyl ether Li-1 and LiCH2CN form a mixed dimeric (1:1) complex, while Li-2 and LiCH2CN form a mixed trimeric (2:1) complex. The dimer undergoes fast exchange between ketenimine and bridged structures. Both (1)J(N-15,Li-6) and (1)J(C-13, Li-6) couplings were observed for the respectively isotopically labeled compounds, In the trimeric complex the CH2CN anion also undergoes fast degenerate exchange between ketenimine and bridged structures, and the complex appears C-2-symmetric on the NMR spectroscopy time scale. Both the dimer and trimer complexes have the bridged acetonitrile anion in common, as indicated by the highly shielded alpha-carbon C-13 NMR shifts (delta -6.1 and -7.4, respectively). In tetrahydrofuran only N-metalated mixed LiCH2CN dimers were observed for both Li-1 and Li-2 with the less shielded C-13 NMR shifts of delta -2.5 and -2.2 for the alpha-carbon of LiCH2CN of the complexes.