The mononuclear barium and dinuclear copper(II) complexes of a 24-membered bibracchial tetraimine Schiff base macrocycle derived from tris(2-aminoethyl)amine and 2,5-diformylfuran

The synthesis and structure of a mononuclear barium complex BaL(3)(ClO4)(2) and the synthesis, structure and properties of a mono-mu-hydroxo-bridged dinuclear copper(II) complex of the macrocycle (L(3)) Cu(2)L(3)(OH)(ClO4)(3) . 1.5H(2)O derived from the cyclocondensation of tris(2-aminoethyl)amine(tren) and 2,5-diformylfuran(dff) are reported. The barium complex crystallises in the monoclinic space group C2/c and has unit-cell dimensions a = 18.868(5), b = 11.635(2), c = 30.376(6) Angstrom, beta = 95.74(2)degrees with Z = 8. The dinuclear copper(II) complex crystallises in the triclinic space group P (1) over bar (C-i(l)) and has unit-cell dimensions a = 10.907(2), b = 14.836(3), c = 22.805(5) Angstrom, alpha = 85.29(3)degrees beta = 84.70(3)degrees gamma = 85.44(3)degrees with Z = 4. The copper-copper separation is ca. 3.74 Angstrom and the Cu-OH-Cu angle is ca. 150 degrees. There is a strong antiferromagnetic interaction between the metals with -2J = 510 cm(-1).