Spontaneous magnetization below 44 K in (benzo[1,2-d:4,5-d′]bis[1,3,2]dithiazole) · FeCl4 driven by evaporation of crystal solvent

An organic/inorganic hybrid system, (benzo[1,2-d:4,5-d′]bis[1,3,2]dithiazole (=BBDTA))·FeCl4·CH3COCH3, is shown to exhibit a drastic change in magnetism after evaporation of the volatile crystal solvent, acetone. The solvated material, with a crystal structure consisting of ladder-like BBDTA and a honeycomb network of Fe(III)Cl4, exhibits antiferromagnetic ordering at 6.3 K. Magnetic measurements and Mössbauer spectra suggest that the desolvated material includes a ferrimagnetic phase with TN=44.0 K.