A nonanuclear copper(II) cluster incorporating endogenous alkoxo- and exogenous hydroxo bridges containing [Cu3(micro3-OH)] cores.

A remarkable nonanuclear copper(II) complex, , with the composition [Cu9(L)4(micro3-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 micro3-OH, thus yielding the nonacopper core. Variable-temperature (2-290 K) magnetic susceptibility data of , have been analyzed by a "three-J" exchange coupling model (H=-2JSi.Sj), 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.