Evaluating the high-pressure structural response and crystal lattice interactions of the magnetically-bistable organic radical TTTA

Abstract

Magnetic bistability has previously been observed and evaluated in an organic thiazyl radical 1,3,5-triathia-2,4,6-triazapentalenyl (TTTA). Herein, the structure-pressure response of TTTA has been evaluated by X-ray diffraction, where a lack of a structural phase transition up to 4.6 GPa certifies that the paramagnetic suppression is caused by a steady decrease in the separation between the moieties containing the radical electron along the π-stacking chains. The intermolecular interactions throughout the crystal lattice have also been calculated using the PIXEL method, and highlight the relative strength of the inter-column interactions in the two known polymorphs of TTTA, which provides extra justification for the cause of the wide magnetic hysteresis and its response to pressure.