Control of Charge Transfer Phase Transition in Iron Mixed-Valence System (n-CnH2n+1)4N[FeIIFeIII(dto)3] (n=3–6; dto = C2O2S2)

Abstract

Iron mixed-valence complex, (n-C3H7)4N[FeIIFeIII(dto)3] (dto = C2O2S2), shows a charge transfer phase transition around 120 K and a ferromagnetic transition at 6.5 K. In order to control the charge transfer phase transition by changing the cation size, we synthesized (n-C n H2n+1)4N[FeIIFeIII(dto)3] (n = 3−6) and investigated the charge transfer phase transition by means of 57Fe Mossbauer spectroscopy. The charge transfer phase transition takes place around 120 K for n = 3 and 4, while it does not take place between 300 K and 4 K for n = 5 and 6.