Heterobinuclear copper(II)-manganese(II) complexes behaving as three-dimensional supramolecular networks via both macrocyclic oxamido-bridges and hydrogen bonds

摘要

Two novel oxamido-bridged heterobinuclear copper(II)-manganese(II) complexes derived from macrocylic oxamido compounds incorporating different blocking ligands were synthesized and characterized by IR and electronic spectroscopy. They are of formula [Cu(L)Mn(phen)(2)](ClO4)(2).1.5H(2)O (1) and [Cu(L)Mn(ntb)](ClO4)(2).H2O (2), where L=1,4,8,11-tetraazacyclotetradecane-2,3-dione, phen=1,10-phenanthroline and ntb=tris(2-benzimidazolylmethyl) amine. The crystal structures of the two complexes have been determined and they consist of binuclear units in which the copper(II) ion is in a square-planar environment and linked to the manganese(II) ion via the exo-cis oxygen atoms of the oxamido macrocyclic ligand, with Cu ... Mn separations of 5.421 (1) and 5.486 Angstrom (2), respectively. The packing of the molecules along the a orientation in 2 results in open channels, which were extended into a three-dimensional hydrogen-bonded supramolecular network. The temperature dependence of the magnetic susceptibility for 1 and 2 were analyzed by means of the Hamiltonian, (H) over cap = -2J (S) over cap (Mn)(S) over cap (Cu), leading to J = -14.2 and -14.7 cm(-1) for 1 and 2, respectively. [References: 44]