A nonanuclear copper(II) cluster incorporating endogenous alkoxo- and exogenous hydroxo bridges containing [Cu3(μ3-OH)] cores

Abstract

A remarkable nonanuclear copper(II) complex, 1, with the composition [Cu₉(L)₄(μ₃-OH)₄(MeOH)₂](ClO₄)₂, in which L is a pentadentate trianionic Schiff-base ligand with N₂O₃ donor atoms, has been characterized by analytical, structural and magnetochemical methods. The structure consists of four dinuclear [Cu₂L]⁺ units linked covalently to a central copper atom by four μ₃-OH, thus yielding the nonacopper core. Variable-temperature (2–290 K) magnetic susceptibility data of 1, have been analyzed by a “three-J” exchange coupling model (H = −2JŜ_i·Ŝ_j), with the simulated coupling constants J′₁ = −189.1 cm⁻¹, J′₂ = −22.7 cm⁻¹, J′₃ = −45.7 cm⁻¹. A rationale for the different strength of antiferromagnetic interactions based on a comparison with those reported in the literature is forwarded.