Structure and Magnetism of a New Dodecanuclear CuII Complex with Acetato and Imidazolato Bridges, Formed by Oxidation of the Chelating Ligand 1,1,7,7‐Tetrakis(imidazol‐2‐yl)‐2,6‐diazaheptane

Abstract

AbstractA novel dodecanuclear copper(II) complex [Cu12(tidhd)4(MeOH)8(CH3COO)8](MeOH)0.8 (Htidhd = 1,1,7,7‐tetrakis(imidazol‐2‐yl)‐2,6‐diaza‐1,6‐heptadiene) with imidazolato and acetato bridging ligands was synthesized by reaction of polyimidazole 1,1,7,7‐tetrakis(imidazol‐2‐yl)‐2,6‐diazaheptane (Htidahp) with copper acetate in a methanol solution. The complex crystallized in the triclinic space group P$\bar 1$ with a = 9.1204(1), b = 13.5139(2), c = 27.6925(5), α = 76.8006(6)°, β = 82.8066(7)°, γ = 76.4594(9)°, Z = 1. Structure analysis shows that the unit cell of the complex contains twelve copper(II) ions in three different coordination environments. The complex is centrosymmetric and the two hexanuclear units are linked by two μ3‐acetate anions [the Cu1−Cu1a distance is 3.5507(7) Å]. The magnetic superexchange interaction via the bridging imidazolate ligand appears to be the most important magnetic interaction in this complex. Magnetic susceptibility measurement vs. temperature in the range of 6−300 K were fitted to the parameters g = 2.05, Ja = −32.0 cm−1 and Jb = −5.45 cm−1. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)