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Temperature and pressure effects on the spin state of ferric ions in the [Fe(sal2-trien)][Ni(dmit)2] spin crossover complex |
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| Authors: | Petra Á Szilágyi Stéphane Dorbes José Antonio Real Christophe Faulmann |
| Institution: | a Laboratoire de Chimie de Coordination, CNRS UPR8241, 205 route de Narbonne, Toulouse, France b Laboratory of Nuclear Chemistry, Eötvös Loránd University, Budapest, Hungary c Instituto de Ciencia Molecular, Universidad de Valencia, Valencia, Spain |
| Abstract: | Thermal and pressure effects have been investigated on the Fe(sal2-trien)]Ni(dmit)2] spin crossover complex by means of Mössbauer spectroscopic, calorimetric, X-ray diffraction and magnetic susceptibility measurements. The complex displays a complete thermal spin transition between the  and  spin states of FeIII near 245 K with a hysteresis loop of ca. 30 K. This transition is characterised by a change of the enthalpy, ΔHHL=7 kJ/mol, entropy, ΔSHL=29 J/Kmol, and the unit cell volume, ΔVHL=15.4 Å3. Under hydrostatic pressures up to 5.7 kbar the thermal transition shifts to higher temperatures by ca. 16 K/kbar. Interestingly, at a low applied pressure of 500 bar the hysteresis loop becomes wider (ca. 61 K) and the transition is blocked at ∼50% upon cooling, indicating a possible (irreversible) structural phase transition under pressure. |
| Keywords: | A Inorganic compounds C High pressure D Magnetic properties D Phase transitions |
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