TY  - JOUR
AU  - Ojwang, Dickson O.
AU  - Grins, Jekabs
AU  - Wardecki, Dariusz
AU  - Valvo, Mario
AU  - Renman, Viktor
AU  - Häggström, Lennart
AU  - Ericsson, Tore
AU  - Gustafsson, Torbjörn
AU  - Mahmoud, Abdelfattah
AU  - Svensson, Gunnar
AU  - Hermann, Raphael
TI  - Structure Characterization and Properties of K-Containing Copper Hexacyanoferrate
JO  - Inorganic chemistry
VL  - 55
IS  - 12
SN  - 1520-510X
CY  - Washington, DC
PB  - American Chemical Society
M1  - FZJ-2016-04563
SP  - 5924 - 5934
PY  - 2016
AB  - Copper hexacyanoferrate, CuII[FeIII(CN)6]2/3·nH2O, was synthesized, and varied amounts of K+ ions were inserted via reduction by K2S2O3 (aq). Ideally, the reaction can be written as CuII[FeIII(CN)6]2/3·nH2O + 2x/3K+ + 2x/3e– ↔ K2x/3CuII[FeIIxFeIII1–x(CN)6]2/3·nH2O. Infrared, Raman, and Mössbauer spectroscopy studies show that FeIII is continuously reduced to FeII with increasing x, accompanied by a decrease of the a-axis of the cubic Fm3̅m unit cell. Elemental analysis of K by inductively coupled plasma shows that the insertion only begins when a significant fraction, ∼20% of the FeIII, has already been reduced. Thermogravimetric analysis shows a fast exchange of water with ambient atmosphere and a total weight loss of ∼26 wt % upon heating to 180 °C, above which the structure starts to decompose. The crystal structures of CuII[FeIII(CN)6]2/3·nH2O and K2/3Cu[Fe(CN)6]2/3·nH2O were refined using synchrotron X-ray powder diffraction data. In both, one-third of the Fe(CN)6 groups are vacant, and the octahedron around CuII is completed by water molecules. In the two structures, difference Fourier maps reveal three additional zeolitic water sites (8c, 32f, and 48g) in the center of the cavities formed by the −Cu–N–C–Fe– framework. The K-containing compound shows an increased electron density at two of these sites (32f and 48g), indicating them to be the preferred positions for the K+ ions.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000378369900028
C6  - pmid:27258790
DO  - DOI:10.1021/acs.inorgchem.6b00227
UR  - https://juser.fz-juelich.de/record/817987
ER  -