The heterocyclic diradical benzo-1,2:4,5-bis(1,3,2-dithiazolyl). Electronic, molecular and solid state structure

Crystals of the heterocyclic diradical benzo-1,2:4,5-bis(1,3,2-dithiazolyl) (BBDTA) were grown and characterized. X-ray crystallographic analysis revealed that the compound consists of discrete, unassociated molecules that form slipped stacks along the x direction, with the molecular plane making an angle of 32.4 degrees to the x axis. Electron resonance spectrometry showed signals characteristic of partially associated materials and free diradicals. It was also indicated by ab initio calculations that there is a small separation between the triplet and singlet diradical states, measuring approximately 0.5 kcal/mol. Magnetic susceptibility measurements indicated that BBDTA is diamagnetic.