Synthesis, structure and magnetic properties of hydroxyquinaldine-bridged cobalt and nickel cubanes

Nickel and cobalt heterocubanes have been synthesised from dinuclear complexes. The use of 8-hydroxyquinaldine leads to a rhombohedral distortion in two faces of the cubes. Both cubes were studied by paramagnetic NMR, which shows that they are stable in solution. Magnetic measurements show that the coupling within both molecules is overall antiferromagnetic. The magnetic data for the nickel cube has been modelled, and shows that the coupling consists of two ferromagnetically coupled pairs which are antiferromagnetically coupled to give a diamagnetic ground state.