HETERODINUCLEAR NI(II)M(II) (M=PB, MN, FE, CO, NI, CU, ZN) COMPLEXES OF A PHENOL-BASED DINUCLEATING MACROCYCLE WITH DISSIMILAR 4-COORDINATION AND 5-COORDINATION SITES

An Ni(II)Pb(II) complex [NiPb(L)](ClO4)2.H2O has been obtained by temp late reaction, where L2- is the dinucleating macrocycle with two 2,6-d i(iminomethyl)-4-methylphenolate entities combined by two lateral chai ns, -(CH2)2- and -(CH2)2NH(CH2)2-, at the imino nitrogens. The Ni and Pb ions are located at the 4-coordination site with the chain -(CH2)2- and the 5-coordination site with the chain -(CH2)2NH(CH2)2- of the ma crocycle, respectively. By the use of the Ni(II)Pb(II) complex as the precursor a series of Ni(II)M(II) complexes [NiM(L)](ClO4)2 (M = Mn, F e, Co, Ni, Cu, Zn) have been obtained in hydrated or solvated forms an d characterized by IR, H-1 NMR and UV-Vis spectra, magnetic measuremen ts, and cyclic voltammetry. Cyclic voltammograms of the Ni(II)M(II) co mplexes show the Ni(II)/Ni(I) reduction at -1.0 to -1.1 V versus SCE. The oxidation of the Fe(II) of the Ni(II)Fe(II) complex occurs at +0.4 3 V whereas the oxidation of the Mn(II) of the Ni(II)Mn(II) complex an d the Co(II) of the Ni(II)Co(II) complex does not occur up to +1.3 V.