Charge transfer phase transition with reversed thermal hysteresis loop in the mixed-valence Fe9[W(CN)8]6·xMeOH cluster†
Abstract
A bimetallic pentadecanuclear cyanido-bridged {Fe9[W(CN)8]6 (MeOH)24}·xMeOH cluster of an FeII/III–WIV/V mixed valence nature, reveals a reversible single-crystal-to-single-crystal transformation, concomitant with metal-to-metal charge transfer between Fe and W ions. The dominance of HSFeII–NC–WV units at a high temperature, and HSFeIII–NC–WIV units at a low temperature, leads to an unprecedented reversed thermal hysteresis loop in magnetic measurements.