The reaction of N,N'-dimethyl-N,N'-ethylenebis(5-bromo-3-formyl-2-hydroxybenzylaminato)copper(II) with ethylenediamine in aqueous DMF with excess perchloric acid resulted in the [2:2] cyclic condensation of the constituents, providing the dinuclear Cu(II) complex [Cu2(H2R)](ClO4)2. It crystallizes in the monoclinic space group P2(1)/c, with a = 19.603(3) A, b = 13.370(2) A, c = 21.072(3) A, beta = 98.87(1) degrees, V = 5456(1) A3, and Z = 4. The ligand R4- has two N(amine)2O2 and two N(imine)2O2 metal-binding sites sharing two phenolic oxygens, and [Cu2(H2R)](ClO4)2 has the two Cu(II) ions in the N(imine)2O2 sites and two protons in the N(amine)2O2 sites. [Cu2(H2R)](ClO4)2 was converted by neutralization into [Cu2(R)], from which mixed-metal Cu(II)2M(II)2 complexes [Cu2M2(R)Cl4] (M = Co(II), Ni(II), Zn(II)) were derived. [Cu2Co2(R)Cl4]*2CHCl3*H2O crystallizes in the monoclinic space group C2/c, with a = 32.514(3) A, b = 12.246(3) A, c = 19.827(2) A, beta = 126.082(1) degrees, V = 6380(1) A3, and Z = 4. [Cu2Zn2(R)Cl4]*2CHCl3*H2O crystallizes in the monoclinic space group C2/c, with a = 32.53(1) A, b = 12.242(2) A, c = 19.729(9) A, beta = 126.03(3) degrees, V = 6354(4) A3, and Z = 4. The two complexes are isotructural and have a dimer-of-dimers structure with two separated Cu(II)M(II) units. In each dinuclear unit, the Cu(II) is bound to the N(imine)2O2 site and the M(II) is bonded to a phenolic oxygen and two nitrogens of the N(amine)2O2 site. The Cu(II) and M(II) ions are bridged by a phenolic oxygen and an exogenous chloride ion. The Cu(II)2Ni(II)2 complex has a defect double-cubane structure. Cryomagnetic studies for the Cu(II)2Co(II)2 complex indicate an antiferromagnetic spin-exchange interaction within each dinuclear Cu(II)Co(II) unit (J = -9.5 cm(-1) based on H = -2JS(Cu)S(Co)). The Cu(II)2Ni(II)2 complex shows a weak antiferromagnetic interaction between the adjacent Cu(II) and Ni(II) ions (-3.5 cm(-1)) and a weak ferromagnetic interaction between the two Ni(II) ions (+2.0 cm(-1)).

The dinucleating macrocyclic ligands (L(2;2))(2-) and (L(2;3))(2-), comprised of two 2-[(N-methylamino)methyl]-6-(iminomethyl)-4-bromophenolate entities combined by the -(CH(2))(2)- chain between the two aminic nitrogen atoms and by the -(CH(2))(2)- or -(CH(2))(3)- chain between the two iminic nitrogen atoms, have afforded the following M(II)Cu(II) complexes: [CoCu(L(2;2))](ClO(4))(2).MeCN (1A), [NiCu(L(2;2))](ClO(4))(2) (2A), [ZnCu(L(2;2))](ClO(4))(2).0.5MeCN.EtOH (3A), [CoCu(L(2;3))(MeCN)(2-PrOH)](ClO(4))(2) (4A), [NiCu(L(2;3))](ClO(4))(2) (5A), and [ZnCu(L(2;3))](ClO(4))(2).1.5DMF (6A). [CoCu(L(2;2))(MeCN)(3)](ClO(4))(2) (1A') crystallizes in the monoclinic space group P2(1)/n, a = 11.691(2) A, b = 18.572(3) A, c = 17.058(3) A, beta= 91.18(2) degrees, V = 3703(1) A(3), and Z = 4. [NiCu(L(2;2))(DMF)(2)](ClO(4))(2) (2A') crystallizes in the triclinic space group P(-)1, a = 11.260(2) A, b = 16.359(6) A, c = 10.853(4) A, alpha= 96.98(3) degrees, beta= 91.18(2) degrees, gamma= 75.20(2) degrees, V = 1917(1) A(3), and Z = 2. 4A crystallizes in the monoclinic space group P2(1)/c, a = 15.064(8) A, b = 11.434(5) A, c = 21.352(5) A, beta= 95.83(2)degrees, V = 3659(2) A(3), and Z = 4. The X-ray crystallographic results demonstrate the M(II) to reside in the N(amine)(2)O(2) site and the Cu(II) in the N(imine)(2)O(2) site. The complexes 1-6 are regarded to be isomeric with [CuCo(L(2;2)))](ClO(4))(2).DMF (1B), [CuNi(L(2;2)))](ClO(4))(2).DMF.MeOH (2B), [CuZn(L(2;2)))](ClO(4))(2).H(2)O (3B)), [CuCo(L(2;3)))](ClO(4))(2).2H(2)O (4B), [CuNi(L(2;3)))](ClO(4))(2) (5B), and [CuZn(L(2;3)))](ClO(4))(2).H(2)O (6B) reported previously, when we ignore exogenous donating and solvating molecules. The isomeric M(II)Cu(II) and Cu(II)M(II) complexes are differentiated by X-ray structural, magnetic, visible spectroscopic, and electrochemical studies. The two isomeric forms are significantly stabilized by the "macrocyclic effect" of the ligands, but 1A is converted into 1B on an electrode, and 2A is converted into 2B at elevated temperature.

The dinucleating macrocyclic ligand (L2;2)2−, prepared by the [1:1] cyclic condensation of N,N′-dimethyl-N,N′-ethylenedi(5-bromo-3-formyl-2-hydroxybenzylamine) and ethylenediamine, has dissimilar N(amine)2O2 and N(imine)2O2 metal-binding sites sharing two phenolic oxygen atoms. It has afforded μ-acetato-di-μ-phenolato-metal(II)cobalt(II) complexes (metal(II) = FeII, CoII, NiII, CuII, ZnII). X-ray crystallographic studies indicate that the MII is bound to the N(amine)2O2 site and has a square-pyramidal geometry with an acetate oxygen at the axial site. The CoII bound to the N(imine)2O2 site has a square-pyramidal geometry with an acetate oxygen at the apex or a distorted octahedral geometry with further coordination of a methanol molecule. The CoII in the N(imine)2O2 site is of low-spin and has one unpaired electron in its dz2 orbital. Magnetic studies indicate an antiferromagnetic interaction in the FeCo and CoCo complexes whereas a ferromagnetic interaction in the NiCo and CuCo complexes. The magnetic properties of the complexes are discussed in terms of the electronic structure of the MII ion and the dinuclear MCo core structure.

Dinuclear hydroxo ZnIIZnII and ZnIIBaII core complexes, derived from a macrocyclic compartmental ligand, are examined in their hydrolytic activity toward tri(p-nitrophenyl) phosphate (TNP) and sodium di(p-nitrophenyl) phosphate (NaDNP) in aqueous DMSO. TNP is hydrolyzed by both complexes. On the other hand, DNP− is hydrolyzed by the ZnBa complex but not by the ZnZn complex.

The reaction of N,N′-dimethyl-N,N′-trimethylenedi(3-aminomethyl-5-methylsalicylaldehydato)copper(II) with 1,3-diaminopropane in DMF afforded the [1+1] condensation product [Cu(L)] and the [2+2] condensation product [Cu2(R)]. The dinucleating macrocyclic ligand (L)2− has one N(amine)2O2 and one N(imine)2O2 metal-binding sites sharing two phenolic oxygen atoms and the tetranucleating macrocyclic ligand (R)4− has two N(amine)2O2 and two N(imine)2O2 sites in an alternate arrangement in the macrocyclic framework. The mixture of [Cu(L)] and [Cu2(R)] was treated with CuCl2 to give [Cu2(L)Cl2] (1a) and [Cu4(R)Cl4] (2a), which were separated based on different solubility in methanol. 1a and 2a were converted into [Cu2(L)](ClO4)2 (1b) and [Cu4(R)(dmf)2](ClO4)4·2H2O (2b), respectively, by the treatment with AgClO4. 1a and 1b each has a dinuclear core doubly bridged by the phenolic oxygen atoms. The crystal structure of [Cu4(R)(dmf)2](ClO4)4·2DMF·H2O·PrOH (PrOH = 2-propanol) (2b′) was determined by X-ray crystallography. It has a dimer-of-dimers structure where each N(amine)2O2 entity accommodates one Cu ion in the usual tetradentate chelating mode, whereas each N(imine)2O2 entity assumes a spread shape to combine one Cu ion with its NO donor atoms and another Cu ion with the remaining NO donor atoms. 2b can be converted into 2a in the presence of chloride ion. Based on magnetic and visible spectral studies, 2a is supposed to have a folded structure of 2b with two Cu–Cl–Cu linkages.