On the Lanthanide Ferrocyanides KLnFe(II)(CN)6·xH2O (Ln=La–Lu): Characterization and Thermal Evolution

Local Structure in Americium and Californium Hexacyanoferrates – Comparison with Their Lanthanide Analogues

“…[13] The main bands due to the cyano stretching vibration are located between 2000 and 2200 cm -1 and are shown in 3-motif exhibits a peak at 2116 cm -1 , which represents the signature of the cyano groups of /Fe III units that are slightly coordinated with potassium atoms. [29] The spectrum of the [Fe II (CN) 6 ] 4-motif exhibits two bands at 2022 and 2039 cm -1 .…”

“…Finally, the third series involves Ln = Eu to Lu. They all occur in the orthorhombic space group: KLnFe II (CN) 6 ·3.5H 2 O crystallizes in the Cmcm space group, [13,14,15] while KLnFe II -(CN) 6 ·3H 2 O crystallizes in the Pnma (or Pbnm, with {a,b,c} = {c,a,b}) space group. [16,17] The difference between the two space groups is the coordination number of the lanthanide atom: in the Cmcm group the lanthanide cation is ninecoordinate as in the La-Nd series; in the Pnma group the lanthanide cation is eight-coordinate to six nitrogen atoms and only two water molecules.…”

Charge transport properties in microcrystalline KDyFe(CN)6

“…All the peaks in the powder X-ray diffraction pattern can be indexed in an orthorhombic Cmcm space group with unit-cell volume V equal to 615.0(2) Å 3 , where a ¼ 7.271(1) Å , b ¼ 12.460(2) Å , and c ¼ 13.590(2) Å in agreement with ionic radii values. The morphology studied by TEM, was found to be the same as previous work [22], i.e., spherical particles with 1 mm size. The crystal structure of KDyFe(CN) 6 Á 3.5H 2 O [23] is a three-dimensional (3D) network of corner-sharing FeC 6 and DyN 6 O 2.5 units as shown in Fig.…”

“…From a structural point of view, these materials are attractive due to the possible systematic study in relation with the electrochemical responses. The lanthanide ion size involves an important structural deformation from the Prussian Blue structure: KLnFe(CN) 6 [17][18][19][20] and KLnFe(CN) 6 Á 3.5H 2 O (Ln ¼ Gd-Lu) [21][22][23] crystallize, respectively, in the hexagonal space group P63/m and in the orthorhombic space group Cmcm. Otherwise this flexibility is demonstrated by the existence of Na + to Cs + in alkali ion site without major structural deformation [24].…”

Synthesis and structure of some nano-sized rare-earth metal ions doped potassium hexacyanoferrates

“…Alike the other HCFs, the KR-HCF compounds are also expected to have efficient electrocatalytic and charge-storing properties. However, only a few reports have been published on these and related materials so far [8,[12][13][14], and this area is still wide open for investigation. Moreover, with nano-sized particles of these compounds one can are expect further enhancement of the useful properties.…”