Fumanal Quintana, MaríaDeumal i Solé, Mercè2017-12-222017-12-222016-08-141463-9076https://hdl.handle.net/2445/118852Semiquinone-bridged bisdithiazolyl-based radicals (XBBO) are appealing purely organic magnetic building blocks for the synthesis of new functional materials. Remarkably, for the phenyl-derivative PhBBO, the rationalization of its magnetism becomes a proof of concept that DFT can dramatically fail to evaluate JAB magnetic interactions between purely organic radical pairs. Instead, wavefunction-based methods are required. Once JAB's are fully characterized, the magnetic topology of PhBBO is disclosed to consist of ferromagnetic FM π-stacks that are very weakly coupled (by FM and AFM JAB interactions). The magnetic susceptibility χT(T) and magnetization M(H) of PhBBO are then calculated using a first-principles bottom-up approach. The study of the unit cell contraction upon cooling from room temperature to zero-Kelvin is relevant to propose a suitable model for the phase transition that occurs at 4.5 K. A simplistic picture tells us that the antiparallel-aligned 1D-FM-chains convert into domains of weakly either FM- or AFM-coupled 1D-FM-chains. Accordingly, the presence of these domains may introduce geometrical spin frustration below 4.5 K.12 p.application/pdfengcc-by (c) Fumanal Quintana, María et al., 2016http://creativecommons.org/licenses/by/3.0/esMagnetismeRadicals (Química)Compostos orgànicsMagnetismRadicals (Chemistry)Organic compoundsinfo:eu-repo/semantics/article6695892017-12-22info:eu-repo/semantics/openAccess27412491