DINUCLEAR CU(II)M(II) (M=CO, NI, CU OR ZN) AND CUIICUI COMPLEXES OF A PHENOL-BASED DINUCLEATING MACROCYCLE WITH DISSIMILAR N2O2 AND N2O2S SITES

A dinucleating macrocycle H(2)L with two 2,6-bis(iminomethyl)-4-methylphenolate entities combined through two lateral chains, CH2CH2 and CH2CH2SCH2CH2, at the imino nitrogens has been obtained as a mononuclear copper(II) complex [CU(H(2)L)][ClO4](2). It reacted with a second metal ion under alkaline conditions to form dinuclear complexes [CU(II)M(II)L(NCS)(2)]. H2O (M=Co, Ni or Zn), [CU(II)Cu(II)L][ClO4](2) and [CU(II)CU(II)L]ClO4. The crystal structure of the dimethylformamide adduct, [CuZnL(NCS)(2)]. dmf, reveals the discrete CuZn dinuclear structure bridged by the two phenolic oxygens of (L)(2-). Th, Cu-II resides at the site with the CH2CH2 lateral chain and assumes a square-pyramidal geometry together with an isothiocyanato nitrogen at the apex. The Zn-II is at the site with the CH2CH2SCH2CH2 chain and assumes a similar square-pyramidal geometry with an isothiocyanato nitrogen at the apex. The sulfur on the lateral chain is not co-ordinated bit disposed to the Zn-II with the Zn ... S separation of 3.48 Angstrom. An antiferromagnetic spin exchange operates in the Cu(II)M(II) (M = Co, Ni or Cu) complexes (J = -32 cm(-1) for M = Co, -90 cm(-1) for M = Ni and -440 cm(-1) for M = Cu based on H = -2JS(1)S(2)). In cyclic voltammograms of [Cu(II)CU(II)L][ClO4](2) and [CU(II)CU(I)L]ClO4 the copper ion at the site with:the CH2CH2SCH2CH2 lateral chain shows a reversible Cu-II-Cu-I redox couple at approximate to + 0.08 V (vs. saturated calomel electrode).