A phenol-based heterodinucleating macrocycle (H(2)L), comprised of two 2-((methylamino)methyl)-6-(iminomethyl)-4-bromophenolate entities bridged by the -(CH(2))(2)- groups between amine nitrogens and by the -(CH(2))(3)- groups between imine nitrogens, displays dissimilar N(amine)(2)O(2) and N(imine)(2)O(2) metal-binding sites sharing the phenolic oxygens and is prepared as a Cu(II)Pb(II) complex [CuPb(L)](ClO(4))(2). An analogous complex [CuPb(L)(BzO)(dmf)]ClO(4) crystallizes in the triclinic space group P&onemacr;, (No. 2), with a = 13.998(2) Å, b = 15.568(2) Å, c = 8.699(2) Å, alpha = 95.32(1) degrees, beta = 92.23(1) degrees, gamma = 82.81(1) degrees, V = 1871.9(5) Å(3), and Z = 2. Refinements based on 3788 reflections with I > 3.00sigma(I) converged with R = 0.058 and R(w) = 0.069. The Cu(II) resides at the N(imine)(2)O(2) site and assumes a planar geometry. The Pb(II) resides at the N(amine)(2)O(2) site and assumes a seven-coordinate geometry by further addition of a dmf molecule and a bidentate benzoate group. The Cu--Pb separation, doubly bridged by the phenolic oxygens, is 3.466(2) Å. The reaction of [CuPb(L)](ClO(4))(2) with metal(II) sulfate salts provides Cu(II)M(II) complexes [CuM(L)](ClO(4))(2).nH(2)O (M = Mn (n = 2), Co (n = 2), Ni (n = 0), Cu (n = 0), Zn (n = 1)). The CuZn complex, [CuZn(L)(AcO)]ClO(4), crystallizes in the triclinic space group P&onemacr;, (No. 2), with a = 12.290(3) Å, b = 13.402(4) Å, c = 11.501(2) Å, alpha = 95.10(2) degrees, beta = 116.68(2) degrees, gamma = 112.00(2) degrees, V = 1491.8(9) Å(3), and Z = 2. Refinements based on 2497 reflections with I > 3.00sigma(I) converge with R = 0.046 and R(w) = 0.034. The Cu(II) is bound at the N(amine)(2)O(2) site and the Zn(II) is bound at the N(imine)(2)O(2) site with a Cu--Zn separation of 2.942(2) Å. Further, the acetate group bridges the two metal ions providing a five-coordinate geometry about both metal ions. The CuM complexes except for the CuZn complex show significant antiferromagnetic spin-exchange within each dinuclear unit. The CuNi complex shows the ESR spectrum of the spin-doublet ground state which demonstrates the delocalization of the unpaired electron over the CuNi core.

No abstract

Complexes of phenol-based dinucleating macrocycles, (L 2;2 ) 2Ϫ and (L 2;4 ) 2Ϫ , comprised of two 4-bromo-2iminomethyl-6-methylaminomethylphenolate moieties combined by an ethylene chain at the amino nitrogens and by an ethylene or a 1,4-tetramethylene chain at the imino nitrogens, have been prepared: mononuclear [Cu(L 2;2 )] and [Cu(L 2;4 )], and dinuclear [PbCu(L 2;2 )][ClO 4 ] 2 and [PbCu(L 2;4 )][ClO 4 ] 2 . The reaction of [Cu(L 2;2 )] and [Cu(L 2;4 )] with MCl 2 salts formed dinuclear [MCu(L 2;2 )Cl 2 ] and [MCu(L 2;4 )Cl 2 ] (M = Mn, Co, Ni, Cu or Zn), respectively. A crystallographic study of [NiCu(L 2;2 )Cl 2 ] indicates the Ni II to reside in the aminic site and the Cu II in the iminic site. The complexes, except for that of M = Zn II , show a significant antiferromagnetic interaction within each dinuclear unit. The reaction of [PbCu(L 2;2 )][ClO 4 ] 2 with MSO 4 salts formed dinuclear Cu II M II perchlorate complexes [CuM(L 2;2 )]-[ClO 4 ] 2 (M = Co, Ni, Cu or Zn). A similar transmetallation for [PbCu(L 2;4 )][ClO 4 ] 2 caused a scrambling of the metal ions. A crystallographic study of [CuNi(L 2;2 )(dmf)][ClO 4 ] 2 ؒMeOH indicates that the Cu II migrates from the iminic to the aminic site to accommodate the Ni II in the iminic site. Kinetic and thermodynamic effects of the macrocycles upon the site selectivity for the metal ions are discussed.

Phenol-based dinucleating macrocycles possessing two dissimilar N(amine)2O2 and N(imine)2O2 metal-binding sites, sharing two phenolic oxygens, have been obtained as mononuclear Cu(II) complexes, capable of incorporating a second metal ion to provide homo- and hetero-dinuclear complexes.

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.