Structure-Properties Relationships in Triplet Ground State Organic Diradicals: A Computational Study

A fast and efficient computational protocol, devised for the accurate calculation of singlet-triplet magnetic splittings in organic diradicals, is here applied to several promising organic magnets, recently considered in the literature. The very good agreement with the measured values, obtained for all investigated compounds, suggests that the present approach could successfully flank the experiment in the design of novel magnetic materials. Indeed, some structure-magnetic properties relationships were rationalized thanks to the theoretical soundness of the adopted multireference approach. In particular the different effects of N· and NO· magnetic moieties, as well as the role of lateral aliphatic chains and phenyl pendant substituents, are discussed in detail.