Synthesis, structure, and magnetic properties of discrete d-f heterodinuclear complexes designed from tetrahedrally distorted [Cu(salabza)] (H2salabza = N,N'-bis(salicylidene)-2-aminobenzylamine) and [Ln(hfac)3] (Hhfac = 1,1,1,5,5,5-hexafluoroacetylacetone, Ln = Gd or Lu)

A tetrahedrally distorted mononuclear copper(II) complex, [Cu(salabza)] 1, and two dinuclear CuLn complexes, [Cu(salabza)Ln(hfac)(3)] (Ln=Gd 2 or Lu 3), were synthesized and their molecular structures determined, where H(2)salabza and Hhfac denote N,N'-bis(salicylidene)-2-aminobenzylamine and 1,1,1,5,5,5-hexafluoroacetylacetone, respectively. In complex 1 the deviations of the four co-ordinating atoms (O(1), O(2), N(1) and N(2)) of salabza(2-) and the copper atom from the least-squares equatorial plane O(1)O(2)N(1)N(2) indicate the tetrahedral distortion around Cu. In 2 and 3 the Cu-II and Ln(III) are bridged by the two phenolic oxygens of salabza(2-). The Cu ... Ln distances are 3.2481(8) Angstrom for 2 and 3.1825(7) Angstrom for 3. The structures of 2 and 3 were found to consist of a perfectly discrete dinuclear CuLn unit, the shortest intermolecular Cu ... Cu, Cu ... Ln and Ln ... Ln distances being 6.002(1), 7.522(1) and 8.507(1) Angstrom for 2, and 5.998(1), 7.509(1) and 8.584(1) Angstrom for 3, respectively. Cryomagnetic susceptibility measurements of 2 in the region of 2 K to room temperature indicated the operation of a ferromagnetic interaction between Cu-II and Gd-III, with J=+0.8 cm(-1) based on H=-2JS(Cu). S-Gd. This was confirmed by measurements of the field dependence of magnetization at 2 K.