Ferromagnetism in dinuclear copper(II)-phenolate complexes with exogenous O-donor bridges:: a comparative study

The copper(II) complex Cu2L(OAc)(H2O)(3.5), 1.3.5H(2)O was obtained and its reactivity in a basic medium investigated. Complex 1.3.5H(2)O shows different reaction patterns in air and in an inert atmosphere. Accordingly, interaction of 1.3.5H(2)O with Me4NOH center dot 5H(2)O in methanol-acetonitrile in air yields the hydroxide complex Cu2L(OH)(H2O)(1.125), 2.1.125H(2)O while Cu2L(OMe)(MeOH)(0.5)(H2O), 3.0.5MeOH center dot H2O is isolated under an argon atmosphere. The products 1-3 were fully characterised and single crystals of {[Cu2L(OAc)]center dot MeCN center dot 3.5H(2)O}(2), 1 center dot MeCN center dot 3.5H(2)O, {[Cu2L(OH)]center dot MeCN center dot 1.125H(2)O}(2), 2.MeCN center dot 1.125H(2)O and [Cu2L(OMe)]center dot 0.5MeOH center dot H2O, 3.0.5MeOH center dot H2O solved. The single X-ray Study shows that 1-3 are dinuclear complexes with,in endogenous phenol oxygen and an exogenous O-bridge. Magnetic characterisation of the three dinuclear complexes was performed, showing ail apparent anomalous intramolecular ferromagnetic coupling between the metal atoms in all casess