Valence-Tautomeric RbMnFe Prussian Blue Analogues: Composition and Time Stability Investigation

✍ Scribed by Lionel Salmon; Esther J. M. Vertelman; Carlos Bartual Murgui; Saioa Cobo; Gábor Molnár; Petra J. van Koningsbruggen; Azzedine Bousseksou

• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 435 KB
• Volume: 2009
• Category: Article
• ISSN: 1434-1948
• DOI: 10.1002/ejic.200800978

✦ Synopsis

Abstract

Three different stoichiometric forms of Rb__~x~Mn[Fe(CN)~6~]~y~__·__z__H~2~O [x = 0.96, y = 0.98, z = 0.75 (1); x = 0.94, y = 0.88, z = 2.17 (2); x = 0.61, y = 0.86, z = 2.71 (3)] Prussian blue analogues were synthesized and investigated by magnetic, calorimetric, Raman spectroscopic, X‐ray diffraction, and ^57^Fe Mössbauer spectroscopic methods. Compounds 1 and 2 show a hysteresis loop between the high‐temperature (HT) Fe^III^(S = 1/2)–CN–Mn^II^(S = 5/2) and the low‐temperature (LT) Fe^II^(S = 0)–CN–Mn^III^(S = 2) forms of 61 and 135 K width centered at 273 and 215 K, respectively, whereas the third compound remains in the HT phase down to 5 K. The splitting of the quadrupolar doublets in the ^57^Fe Mössbauer spectra reveal the electron‐transfer‐active centers. Refinement of the X‐ray powder diffraction profiles shows that electron‐transfer‐active materials have the majority of the Rb ions on only one of the two possible interstitial sites, whereas nonelectron‐transfer‐active materials have the Rb ions equally distributed. Moreover, the stability of the compounds with time and following heat treatment is also discussed.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)