Two novel heterometallic complexes [Cu2Fe2(HL(1))2(H2L(1))2]·10DMSO () and [Cu2Fe2(HL(2))2(H2L(2))2]·2DMF () have been prepared using the open-air reaction of copper powder, iron(ii) chloride and DMSO () or DMF () solutions of the polydentate Schiff base (H4L(1), ; H4L(2), ) formed in situ from salicylaldehyde () or 5-bromo-salicylaldehyde () and tris(hydroxymethyl)aminomethane. Crystallographic analysis revealed that both compounds are based on the centrosymmetric tetranuclear core {Cu(II)2Fe(III)2(μ-O)6} where metal centres are joined by μ-O bridges from the deprotonated ligands forming a nonlinear chain-like arrangement. Variable-temperature (1.8-300 K) magnetic susceptibility measurements of and showed a decrease of the effective magnetic moment value at low temperature, indicative of antiferromagnetic coupling (JCu-Fe/hc = -10.2 cm(-1), JFe-Fe/hc = -10.5 cm(-1) in , JCu-Fe/hc = -10.5 cm(-1), JFe-Fe/hc = -8.93 cm(-1) in ) between the magnetic centres in both compounds. They reveal an exceptionally high catalytic activity in the oxidation of cyclohexane with hydrogen peroxide under mild conditions, with the best observed yield/TON combined values of 36%/596 and 44%/1.1 × 10(3) for and , respectively.