Adipato‐Bridged Copper(II) Complexes

Abstract

AbstractReactions of Cu(ClO4)2·6H2O, adipic acid, and 2,2′‐bipyridine/1,10‐phenanthroline in aqueous methanolic solutions afforded four adipato‐bridged CuII complexes, {[Cu(phen)2]2(C6H8O4)}(ClO4)2 (1), {[Cu(phen)2]2(C6H8O4)}(ClO4)2·1.33H2O (2), [Cu2(phen)2(H2O)]2(C6H8O4)2(ClO4)4 (3), and {[Cu2(bpy)2(H2O)]2(C6H8O4)2}(ClO4)4·2H2O (4) (phen = 1,10‐phenanthroline, bpy = 2,2′‐bipyridine, C6H8O4 = adipate anion). The centrosymmetric adipato‐bridged dumbbell‐like dinuclear complex cations {[Cu(phen)2]2(C6H8O4)}2+ in 1 and 2, through aromatic stacking interactions, are assembled into supramolecular (4,4) networks, and twofold interpenetration of the networks completes the 3D supramolecular architectures with counterions as well as the lattice water molecules in voids. The characteristic secondary building units in 3 and 4 are the centrosymmetric double‐semi‐paddle‐wheel oftetranuclear {[Cu2(phen)2(H2O)]2(COO)4} and{[Cu2(bpy)2(H2O)]2(COO)4} clusters, respectively, which are interconnected by adipato ligands to form (4,4) networks. The resulting networks, through interlayer‐stacking interactions, are assembled into a 3D open framework with counterions as well as the lattice water molecules in channels. Magnetic studies of 3 and 4 suggest significant antiferromagnetic coupling interactions between CuII ions bridged by the syn–syn carboxylate groups, whereas weak ferromagnetic coupling is observed between two symmetry‐related copper(II) ions bridged by the μ2‐O atoms. Cyclic voltammograms of 3 and 4 exhibit similar redox behaviors and display two quasireversible couples. The thermal decompositions of 3 and 4 are also described.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)