Density functional theory prediction of enhanced photomagnetic properties of nitronyl nitroxide and imino nitroxide diradicals with substituded dihydropyrene couplers.

We predict the photoswitching magnetic properties of four substituted dihydropyrenes from density functional broken-symmetry calculations. The magnetic exchange coupling constants differ up to 9.44 cm(-1). The intramolecular exchange interactions are ferromagnetic in nature. The calculated coupling constants are much larger than those reported earlier for photomagnetic organic molecules.