MIGRATORY TRANSMETALATION IN DIPHENOXO-BRIDGED CUIIMII COMPLEXES OF A DINUCLEATING MACROCYCLE WITH N(AMINE)(2)O-2 AND N(IMINE)(2)O-2 METAL-BINDING SITES

摘要

A phenol-based heterodinucleating macrocycle (H2L), comprised of two 2-((methylamino)methyl)-6-(iminomethyl)-4-bromophenolate entities bridged by the -(CH2)(2)- groups between amine nitrogens and by the -(CH2)(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)](ClO4)(2). An analogous complex [CuPb(L)(BzO)-(dmf)]ClO4 crystallizes in the triclinic space group <(P)over bar 1>, (No. 2), with a = 13.998(2) Angstrom, b = 15.568(2) Angstrom, c = 8.699(2) Angstrom, alpha = 95.32(1)degrees, beta = 92.23(1)degrees, gamma = 82.81(1)degrees, V = 1871.9(5) Angstrom(3), and Z = 2. Refinements based on 3788 reflections with I > 3.00 sigma(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) Angstrom. The reaction of [CuPb(L)](ClO4)(2) with metal(II) sulfate salts provides (CuMII)-M-II complexes [CuZn(L)(AcO)]ClO4). 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)]ClO4, crystallizes in the triclinic space group <(P)over bar 1>, (No. 2), with a = 12.290(3) Angstrom, b = 13.402(4) Angstrom, c = 11.501(2) Angstrom, alpha = 95.10(2)degrees, beta = 116.68(2)degrees, gamma = 112.00(2)degrees, V = 1491.8(9) Angstrom(3), and Z = 2. Refinements based on 2497 reflections with I > 3.00 sigma(1) 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) Angstrom. 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. [References: 41]