“…A promising synthetic route toward stable organic polyradicals would be to protect the magnetic centers with cumbersome and inert chemical groups, but this proposal faces against a number of experimental and theoretical difficulties. From the experimental point of view, the group of Rajca has recently succeeded in synthetizing several organic polyradicals 4,7,8 and, in particular, a very promising tetraradical molecule based on aminyl groups, which is the object of the present investigation. 9 Full experimental characterization of such species is, however, not yet fully feasible, and, in particular, several difficulties are encountered in the experimental estimate of the energy gap among the different spin states.…”