(BEDT-TTF)8[SiW12O40] and (BEDT-TTF)8[PMo12O40]: Two New Examples of 1D Organic Antiferromagnetic Systems

Abstract (BEDT-TTF)8[PMo12O40] has been characterized by EPR, UV-visible, IR spectroscopy and by static magnetic susceptibility. It contains the mixed-valence paramagnetic anion [PMo12o40]4- and the BEDT-TTF molecules are ionised with an average degree of charge p=+0. 5. The compound is isomorphous with (BEDT-TTF) 8[SiW12O40], the crystal structure of which is known. The magnetic properties of both salts have been studied. They are highly localised, low-dimensional spin S=l/2 systems, with one spin per BEDT-TTF dimer.

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