摘要:
Tetranuclear Cu(11) complexes of N-(2-hydroxymethylphenyl)salicylidencimine (H(2)L1-H) and its homologues (5-CH3: H(2)L1-Me, 5-Cl: H(2)L1-Cl), [Cu(Ll-H)](4).3H(2)O (1), [Cu(L1-Me)](4).2CH(2)Cl(2) (2), and [Cu(L1-Cl)](4) . 2CH(2)Cl(2) (3), have been characterized by X-ray crystal structure analyses and magnetic measurements. The structure analyses revealed that the complexes 1-3 have a defective double-cubane tetra copper(H) core connected by mu(3)-alkoxo bridges. The intramolecular Cu...Cu distances are in the range from 5.251(2)-5.256(3) Angstrom for the longest to 3.0518(9)-3.092(2) Angstrom for the shortest. Each Cu(11) ion has a square-pyramidal geometry and the dihedral angles between adjacent Cu(II) basal planes are almost right angles. Magnetic measurements of the present complexes indicate that weak antiferromagnetic interactions (J = -15 to -19 cm(-1)) between neighboring copper(H) ions are dominant in these tetracopper cores. (C) 2004 Elsevier B.V. All rights reserved.