Synthesis and Crystal Structure of Ammonium, Strontium Hexacyanoferrate(II) Dihydrate

Abstract

The molecular structure of Sr(NH 4 ) 2 [Fe(CN) 6 ]Á 2H 2 O, was determined by X-ray diffraction methods. It crystallizes in the orthorhombic Pnma space group with a = 13.1420(3), b = 14.1656(4), c = 7.3364(2) A ˚, and Z = 4. The structure was solved and refined. The iron(II) complex is located on a crystallographic inversion center with the metal in a nearly perfect octahedral environment [Fe-C bond distances from 1.919(4) to 1.939(4) A ˚]. The Sr(II) ion lies on a crystallographic mirror plane, sandwiched between two nearly square Archimedean anti-prism basis, angled 458 from each other. One base is formed by the two water molecules located on the mirror plane [SrÁÁÁOw distances of 2.741(4) and 2.636(4) A ˚] and by a pair of mirror-related cyanide N-atom [d(SrÁÁÁN) = 2.676(3) A ˚], the other one by two pairs of mirror-related cyanide nitrogen atoms [SrÁÁÁN distances of 2.649(3) and 2.640(4) A ˚] of neighboring [Fe(CN) 6 ] 4anions. The infrared absorption spectrum of the compound was also recorded and briefly discussed.

Guest-Activated Forbidden Tilts in a Molecular Perovskite Analogue

“…The hydrated phase 1 ·2H 2 O has a structure with the same basic framework connectivity as 1 but in which the coordination number of Sr 2+ has increased from six to eight in order to accommodate two additional H 2 O molecules. The particular H 2 O arrangements we observe are different from those in the orthorhombic modification of (NH 4 ) 2 SrFe­(CN) 6 ·2H 2 O (accessed via an alternative synthetic route and having a different framework connectivity related to the KLnFe­(CN) 6 · n H 2 O phases) and lead instead to a monoclinic structure with C 2/ c symmetry. For our study it is convenient to consider the hydration pattern in 1 ·2H 2 O in terms of a correlated distortion of B-site coordination environments of the underlying perovskite-like lattice.…”

Ammonium, barium hexacyanoferrate(II) trihydrate

“…), while NH 4 ? deformation mode d(HNH) is observed at 1,418 cm -1 [30,45]. The Raman dispersion spectrum (Fig.…”

“…Anal The crystal structure of Ba(NH 4 ) 2 [Fe(CN) 6 ]Á3H 2 O can be compared with the related Sr(NH 4 ) 2 [Fe(CN) 6 ]Á2H 2 O compound [30]. The strontium complex crystallizes in the orthorhombic space group Pnma with the ferrocyanide complex on an inversion center and the Sr(II) ion sited on a crystallographic mirror plane (Cs) in an eightfold Archimedean square anti-prism coordination.…”

“…We have already reported the crystal structure of ammonium, strontium hexacyanoferrate(II) dihydrate. It crystallizes in the orthorhombic Pnma space group [30].…”

Crystal structure refinement and vibrational analysis of Y[Co(CN)6]·4H2O and its thermal decomposition products

“…The oxides obtained by this method were formed at shorter annealing times and lower temperatures than ceramic methods. The use of a precursor containing the appropriate A/B ratio enforces the formation of ABO 3 perovskites with the precise stoichiometry, thus controlling and preventing any elements segregation generally observed in conventional methods and allowing the synthesis of the desired mixed oxide at very low temperatures [12][13][14][15][16][17][18][19]. The homogeneous mixed oxides so obtained have relatively high surface areas and consequently can be used as catalyst in different chemical reactions [20].…”