Single-crystal high-frequency electron paramagnetic resonance investigation of a tetranuclear iron(III) single-molecule magnet

Single crystals of planar tetranuclear complex Fe4(OCH3)(sub 6)(dpm)(sub 6), which were earlier shown to have a typical single-molecule magnet behavior are studied using a high-frequency electron paramagnetic resonance (EPR) study. It is seen that as the temperature increases, the separation between the individual lines decreases and vanishes, which may be caused due to the contribution of fast relaxing excited states, whose population varies with temperature.