Coordination study of a new class of imine imidazol-2-imine ligands to titanium(IV) and palladium(II)

A new family of ligand precursors, N-(1-(2,6-dimethyl-phenylimino) ethyl)-1,3-bis(aryl) imidazol-2-imine hydrochloride, wherein aryl = 2,4,6-trimethylphenyl (3a) and 2,6-diisopropylphenyl (3b), was prepared and structurally characterised. Deprotonation of the salts yields molecules with delocalised pi-electrons, leading to zwitterionic mesomeric structures. Titanium(IV) (4a, b) and palladium(II) (5a, b) complexes were isolated and also structurally characterised. Two different coordination modes were observed where the ligand is either coordinated in a bidentate fashion as expected, or in a monodentate fashion through the more basic aryliminic nitrogen atom.