Ferromagnetic alternating spin chains

The study of the magnetic properties of heteronuclear species has shown that ferromagnetic coupling is much more common than it was suspected before, because by using different metal ions, or in general different spins, it is much easier to bring into interaction orthogonal magnetic orbitals. These results have been very stimulating, because they have suggested possible strategies to assemble ferromagnetic materials starting from pairs of different spins. The interest for such materials is bound both to the wish to make what has been called the magnetic zoo as complete as possible and also to the possibility of determining which are the possible and also to the possibility of determining which are the conditions under which molecular ferromagnets can be obtained. The design of low dimensional materials is relatively simple using molecular building blocks, and chains are the systems for which more examples are available. In the present paper the case of a chain formed by Cu(II) ions and nytronyl nitroxide radicals is investigated showing a resulting ferromagnetic coupling.