Crystal structure and magnetic properties of a thiazyl organic ferromagnet, BBDTA · GaCl4 with Tc=7.0 K

Three polymorphs, labeled α (plates), β (needles), and γ (blocks), of BBDTA(=benzo[1,2-d:4,5-d′]bis[1,3,2]dithiazole) · GaCl4 were obtained as a mixture of three polymorphs, by recrystallization at −23 °C. The γ-phase showed the ferromagnetic ordering at 7.0 K, in contrast to diamagnetic properties of the α- and β-phases. The crystal structure of the γ-phase exhibited a minimal overlap between the singly occupied molecular orbitals of neighboring molecules, in spite of short interatomic S⋯N distances.