C3-symmetric trinuclear copper(II) species as tectons in crystal engineering

Three new complexes have been obtained using C-3-symmetric trinuclear complexes as tectons; [Cu-3(felden)(NCS)(3)(dmf)(3)] (1), [Cu-3(felden)(mand)(3)]center dot(C2H5)(2)O (2), and [Cu-3(felden)(dca)(3)(C2H5OH)]center dot 2H(2)O (3) (H-3 felden is the Schiff base resulting from the condensation of 2,4,6-triformylphloroglucinol with N,N-dimethylethylenediamine, mand(-) is the anion of the R-mandelic acid and dca(-) is the dicyanamide anion). Compounds 1 and 2 are discrete trinuclear species, while compound 3 is a 2D coordination polymer, constructed from trinuclear nodes and dicyanamido spacers. The variable-temperature magnetic properties of 1-3 have been investigated and they reveal the occurrence of weak antiferromagnetic interactions between the copper(II) ions (-J values ranging from 0.90 to 2.40 cm(-1)) whose size and trend are dependent on the intramolecular copper-copper separation and nature of the basal chromophore at each copper atom.