Coordination-position isomeric MIICuII and CuIIMII (M = Co, Ni, Zn) complexes derived from macrocyclic compartmental ligands

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 -(CH2)(2-) chain between the two aminic nitrogen atoms and by the -(CH2)(2-) or -(CH2)(3-) chain between the two iminic nitrogen atoms, have afforded the following (MCuII)-Cu-II complexes: [CoCu(L-2;2)](ClO4)(2).MeCN (1A), [NiCu(L-2;2)](ClO4)(2) (2A), [ZnCu(L-2;2)](ClO4)(2).0.5MeCN.EtOH (M), [CoCu(L-2;3)(MeCN)-(2-PrOH)](ClO4)(2) (4A), [NiCu(L-2;3)](ClO4)(2) (5A), and [ZnCu(L-2;3)](ClO4)(2).1.5DMF (6A). [CoCu(L-2;2)(MeCN)(3)](ClO4)(2) (W) crystallizes in the monoclinic space group P2(1)/n, a = 11.691(2) Angstrom, b = 18.572(3) Angstrom, c = 17.058(3) Angstrom, beta = 91.18(2)degrees, V = 3703(1) Angstrom(3) and Z = 4. [NiCu(L-2;2)(DMF)(2)](ClO4)(2) (2A') crystallizes in the triclinic space group P (1) over bar, a = 11.260(2) Angstrom, b = 16.359(6) Angstrom, c = 10.853(4) Angstrom, alpha = 96.98(3)degrees, beta = 91.18(2)degrees, gamma = 75.20(2)degrees, V = 1917(1) Angstrom(3) and Z = 2. 4A crystallizes in the monoclinic space group P2(1)/c, a = 15.064(8) Angstrom, b = 11.434(5) Angstrom, c = 21.352(5) Angstrom, beta = 95.83(2)degrees, V = 3659(2) Angstrom(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))](ClO4)(2).DMF (5B), [CuNi(L-2;2))] (ClO4)(2).DMF.MeOH (2B), [CuZn(L-2;2))](ClO4)(2).H2O (3B)), [CuCo(L-2;3))](ClO4)(2).2H(2)O (4B), [CuNi(L-2;3))](ClO4)(2) (5B), and [CuZn(L-2;3))](ClO4)(2).H2O (6B) reported previously, when we ignore exogenous donating and solvating molecules. The isomeric (MCuII)-Cu-II and (CuMII)-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 1113 on an electrode, and 2A is converted into 2B at elevated temperature.