Oxime-functionalized diazamesocyclic derivates and their metal complexes: Effect of the ligand backbones and anions on the generation of novel monomeric and mono-mu-Cl dimeric Cu-II complexes

摘要

Two oxime-functionalized diazamesocyclic derivates, namely, N,N'-bis(acetophenoneoxime)-1,4-diazacycloheptane (H2L1) and N,N'-bis(acetophenonoxime)-1,5-diazacyclooctane (H2L2), have been prepared and characterized. Both ligands (obtained in the hydrochloride form) can form stable metal complexes with Cu-II and Ni-II salts, the crystal structures of which were determined by X-ray diffraction technique. The reactions of H2L1 with Cu(ClO4)(2) and Ni(ClO4)(2) afford a penta-coordinated mononuclear complex [Cu(H2L1)Cl] (.) ClO4 (1) and a four-coordinated monomeric [Ni(HL1)] (.) ClO4 (2), in which the ligand is monodeprotonated. The ligand H2L2 also forms a quite similar mononuclear [Ni(HL2)] (.) ClO4 complex with Ni(ClO4)(2), according to our previous work. However, reactions of different Cu-II salts [Cu(ClO4)(2), CuCl2 and Cu(NO3)(2) for 3, and CuSO4 for 4] with H2L2 in the presence of NaClO4 yield two unusual mono-mu-Cl dinuclear Cu-II complexes [CU2(HL2)(2)Cl] (.) (ClO4) (3), and [Cu-2(H2L2)(HL2)Cl]. (ClO4)(2) (.) (H2O) (4). These results indicate that the resultant Cu-II complexes (1, 3 and 4) are sensitive to the backbones of diazamesocycles and even auxiliary anions. (c) 2005 Elsevier B.V. All rights reserved.