Pressure effect studies in molecular magnetism

We report on temperature dependent magnetic susceptibility and Mossbauer effect studies of the influence of hydrostatic pressure (up to 1.2 GPa) on dynamic electronic structure phenomena in 3d transition metal coordination compounds. The systems under investigation are mononuclear spin crossover compounds of iron (II) and chromium (II), dinuclear complexes of iron (II) exhibiting coexistence of intramolecular anti ferro magnetic coupling and thermal spin crossover, 1D, 2D and 3D polynuclear spin crossover complexes of iron (II), a valence tautomeric system of cobalt (II) showing a thermal transition from a high spin [Co-II (semiquinone)] to a low spin [Co-II (catecholate)] species on lowering the temperature and a photomagnetically active Prussian blue type system with temperature- and pressure induced electron transfer. It is demonstrated that pressure effect studies can be very helpful in elucidating the mechanisms and cooperative interactions of solid state compounds with electronic bistability.