NICKEL(II) AND EUROPIUM(III) COMPLEXES OF THE AMINOPHENOL LIGAND: 2-(DIETHYLAMINO)METHYLPHENOL (N∼OH). CRYSTAL STRUCTURES OF THE Ni(N∼O)2 AND [Eu(NO3)3(HN∼O)2]2 COMPLEXES

Abstract

The first Ni(II) compounds with aminophenol ligands were synthesized by reaction of 2-diethylaminomethylphenol and 2-diethylaminomethyl-4-methylphenol (N ∼ OH) with dehydrated NiCl2 in ethanol. They were characterized as tran-square planar Ni(N ∼ O)2 complexes by NMR and IR spectroscopies, mass spectrometry, elemental analysis and X-ray structure determination. When the ligand was reacted with Eu(NO3)3, the new dimeric complex [Eu(NO3)3(HN ∼ O)2]2 was isolated. Elemental analysis, IR, magnetic moment and X-ray diffraction indicated that in this case formally neutral aminophenol ligands, in their zwitterionic form, are attached to the metal center through the phenolato oxygen and act either as bridging or as terminal groups. Their protonated amino substituents are involved in strong N—H—O hydrogen bridging. The metal shows nine-coordination, the coordination sphere of each europium being completed by three NO3 groups.