New insight in coordination of vic-dioximes: Bis- and tris(E,E-dioximato)Ni(II) complexes
摘要:
N, N'-Bis[allylamino] glyoxime, N,N'-bis[anilino] glyoxime, and N, N'-bis[1,2,3,4- tetrahydro-5-naphthalenamino] glyoxime have been prepared from corresponding amines and (E, E)-dichloroglyoxime. These ligands gave orange-red compound with NiCl(2) in less acidic medium (pH similar to 5) that are bis(E, E-dioximato) nickel(II) complexes {[(E, E)-Ni(HL)(2)]} (1a-3a) and green compounds in acidic medium (pH similar to 2) that are tris(E, E-dioximato) nickel(II) dichloride complexes {[(E, E)- Ni(LH(2))(3)]Cl(2)} (1b-3b). The crystal structures of all complexes have been determined by X-ray diffraction on a single crystal. The study of absorption spectra of these two types of complexes shows that they may be converted to each other by addition of acids (1a-3a) or bases (1b-3b) and there is no way for the amphi form. (C) 2007 Elsevier B. V. All rights reserved.