The crystal structures of a series of dithiadiazolyl free radicals, p-XC6F4CNSSN (X=F,Cl,Br and CN) are described in terms of dipolar interactions which induce chain-like motifs in the solid state, When X=CN two morphologies are observed; the P-phase is polar and undergoes a phase transition to a weakly ferromagnetic state at 36K, an unprecedented temperature for an organic radical. The polar structure which gives rise to weak ferromagnetism in beta -p-NCC6F4CNSSN, also provides a number of other potential solid state properties which may interact independently or cooperatively with the magnetic behaviour.