Dimerisation versus polymerisation: Affects of donor position in isomeric dilithium diamine-bis(phenolate) complexes

The synthesis and structures of isomeric lithium diamine-bis(phenolate) complexes are reported. Deprotonation of the ligands, H2O2NN′tBu [Me2NCH2CH2N(CH2ArOH)2, Ar = 3,5-C6H2-tBu2] and H2O2N2tBu [HOArCH2NMeCH2CH2NMeCH2ArOH, Ar = 3,5-C6H2-tBu2], in diethyl ether affords base-free lithium complexes Li2O2NN′tBu (1) and Li2O2N2tBu (2) upon solvent removal. The dioxane adduct of (1) exhibits a polymeric structure in the solid-state, whereas the dioxane adduct of (2) possesses a dimeric structure. The syntheses of K2O2NN′tBu (3), K2O2N2tBu (4), Zr(O2NN′tBu)Cl2 (5) and Y(O2NN′tBu)Cl(THF), (6), are also reported. The transition metal complexes were isolated in good yields via salt metathesis reactions using 1 or 3.