A new synthetic route towards heterotrimetallic complexes.: Synthesis, crystal structure and magnetic properties of a [CuIIMnIICrIII] trinuclear complex

The heterotrimetallic complex, [{LCuMn(H2O)}{Cr(phen)(C2O4)(2)}](ClO4)center dot H2O (1), has been obtained by assembling heterobinuclear cations, [LCuMn](2+), with [Cr(phen)(C2O4)(2)](-) ions (H2L is the compartmental Schiff-base resulting from the stepwise condensation of 2,6-diformyl-p-cresol with ethylenediamine and diethylenetriamine). The copper(II) and manganese(II) ions are hosted into the compartments of the macrocyclic ligand. [Cr(phen)(C2O4)(2)](-) acts as a ligand, being coordinated through one oxalato oxygen atom to the apical position of the square pyramidal copper(II) ion. The cryomagnetic investigation of 1 reveals an antiferromagnetic interaction between Cu-II and Mn-II within the compartmental ligand (J = -39 cm(-1)). The interaction between Cu-II and Cr-III across the oxalato bridge is negligible. The crystal structure of [LCuPb](ClO4)(2)center dot H2O, a useful precursor in obtaining 3d-3d' complexes, is also reported. (c) 2005 Elsevier B.V. All rights reserved.