Homo- and heterometallic complexes constructed from hexafluoroacetylacetonato and Schiff-base complexes as building-blocks.

Three new homo- and heterotrimetallic complexes have been synthesized and crystallographically characterized: [Cu2(saldmpn)2(<italic>μ</italic>-OCH3)2Cu2(hfac)2] (<bold>1</bold>), [Ni2(valaepy)2(hfac)2] (<bold>2</bold>), [Cu(saldmpn)Co(hfac)2] (<bold>3</bold>) [H2saldmpn is the Schiff-base resulting from condensation of salicylaldehyde with 2,2-dimethyl-1,3-diaminopropane and Hvalaepy results from the reaction of <italic>o</italic>-vanillin with 2-(2-aminoethyl)pyridine)]. The structure of <bold>1</bold> consists of a neutral tetranuclear species that can be viewed as resulting from mutual coordination of one {(hfac)Cu(<italic>μ</italic>-OCH3)2(Cu(hfac)} and two {Cu(saldmpn)} building blocks. Compound <bold>2</bold> is a binuclear complex that results from two {Ni(hfac)(valaepy} fragments, the nickel(II) ions bridged by the two phenoxide-oxygens. The heterobinuclear complex <bold>3</bold> results from coordination of the [Cu(saldmpn)] metalloligand to cobalt(II) from the {Co(hfac)2} unit. The magnetic properties of <bold>1-3</bold> have been investigated from 1.9 to 300 K. An overall ferromagnetic behavior is observed for <bold>1</bold> and <bold>2</bold> leading to <italic>S</italic> = 2 low-lying spin state for each one. In the case of <bold>3</bold>, a non-magnetic ground state results because of the occurrence of an intramolecular antiferromagnetic coupling between the copper(II) ion and the high-spin cobalt(II) ion, this last one behaving as an effective spin <italic>S</italic>eff = ½ at low temperatures where only the ground Kramers doublet of Co(II) is thermally populated. The values of the intramolecular magnetic couplings in <bold>1-3</bold> are compared with those from the literature on related systems. [ABSTRACT FROM AUTHOR]