Gadolinium Potassium Hexacyanoferrate(II) Trihydrate

Abstract

Gadolinium potassium hexacyanoferrate(II) trihydrate, GdKFe(CN)6.3H20, crystallizes in the orthorhombic space group Pnma (No. 62). The structure consists of non-linear cyanide bridges linking octahedrally coordinated Fe atoms and eight-coordinate Gd atoms. Cavities within the structure are occupied by potassium and zeolitic water molecules which are within hydrogen-bonding distance of the water molecules bonded to the Gd atoms, GdN6(H20)2. ReferencesAbrahams, S. C., Lissalde, F. & Bernstein, J. L. (1978). J. Chem.Phys. 68, 1926-1935. © 1996 International Union of Crystallography Printed in Great Britain -all rights reserved CommentThe first ferrocyanide containing a lanthanide atom, CeKFe(CN)6, was described by Robinson (1909).

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

“…Subsequent refinement with FullProf yielded the final cell parameters as a ¼13.62513 70.00057 Å; b¼ 12.51992 7 0.00047 Å and c ¼7.318107 0.00033 Å; and 90 α β γ = = =°. These values seem to be in reasonably good agreement with the reported crystal data for KGd-HCF [25], except for the fact that the space group determined in our analysis is P MMM (No. 47) instead of the reported P NMA (No.…”

“…The unit-cell structure and other crystal details of KGd-HCF are already reported for sufficiently large crystals [25], but not for the nano-sized particles. Nevertheless, this was supposed to give us some idea about the expected solutions and therefore, we started our FullProf analysis with the data for KGd-HCF nanomaterial.…”

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

“…This evolution is a consequence of the actinide and lanthanide contraction upon going to the higher atomic numbers. Conversely, the situation is very different for the distances within the {Fe(CN) 6 [7][8][9][10][11][12][13][14][15][16][17] …”

“…Values of the Debye-Waller factors are comparable for the first shell but differ significantly for further shells (the coordination numbers being fixed by the model used), as these materials are expected to be significantly disordered (radiation from the actinide-specific activity might be an additional origin of increased disorder as mentioned above). [7][8][9][10][11][12][13][14][15][16][17] ). In all of these structures, the distances within the iron octahedron are on the average d(FeC) = 1.91 Ϯ 0.02 Å and d(CN) = 1.15 Ϯ 0.01 Å.…”

“…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. In the nine-coordinate lanthanide compounds, the LnN 6 (H 2 O) 3 polyhedron forms a tricapped trigonal prism in which the lanthanide is bonded to six nitrogen atoms in prismatic sites and three water molecules in the capping positions.…”