Ammonium, barium hexacyanoferrate(II) trihydrate

Abstract

The ammonium, barium hexacyanoferrate(II) trihydrate, Ba(NH 4 ) 2 [Fe(CN) 6 ]Á3H 2 O, has been synthesized for the first time, was characterized by thermogravimetric and differential thermal analysis (TG-DTA), infrared (IR) and Raman spectroscopy and chemical analysis, and its crystal and molecular structures were determined by X-ray diffraction methods. The chemical composition was determined by assaying Ba(II) with EDTA, ammonia nitrogen with Nessler's reagent as indicator and Fe(II) using spectrophotometry with ortho-phenanthroline method. The hydration number was estimated by thermogravimetric analysis. The compound crystallizes in the trigonal R-3c space group. The ferrocyanide anion has an almost perfect octahedral shape with its Fe(II) ion in a crystallographic special position of point symmetry S 6 [d(Fe-C) = 1.912(2) A ˚, d(C-N) = 1.153(3) A ˚]. The barium, ammonium nitrogen and water oxygen atoms are also at lattice special positions with site symmetries D 3 , C 3 and C 2 , respectively. The thermal decomposition process was also studied using TG-DTA, and the products of decomposition were identified by IR spectroscopy. It proposes a mechanism of decomposition.

Guest-Activated Forbidden Tilts in a Molecular Perovskite Analogue

“…The underlying mechanism involves coupling of tilts to the specific pattern of Sr–OH 2 bonds formed during hydration. A similar mechanism is observed in the related Ba-containing framework (first reported in ref ) except that the increase in cation radius drives a different hydration pattern, in turn affecting the symmetry of the forbidden tilt systems activated. So not only do we show how to access unconventional tilt order for these molecular perovskites, but also we establish a methodology through which simple chemical modification might eventually be used to manipulate physical properties that depend on the nature of activated tilts.…”

“…An interesting comparison can be drawn to the Ba-containing analogue (NH 4 ) 2 BaFe­(CN) 6 ·3H 2 O ( 2 ·3H 2 O), first described in ref . In this structurally related compound, the larger Ba 2+ cation coordinates three H 2 O molecules to give a total coordination number of nine and a coordination geometry with D 3 point symmetry.…”

Supramolecular Solid Complexes between Bis-pyridinium-4-oxime and Distinctive Cyanoiron Platforms

“…1cr. Then, higher thermal energy, in the range of 190 to 210 °C, leads to analogous w defined exothermic weight loss, characteristic for cyanoiron(II) complexes [25], reveal their analogous composition to (TOXO)2[Fe(CN)6], which continues to decompose on ther heating. These gravimetric results show that the change in color between 1a and is accompanied by extrication of eight water molecules per chemical formula unit.…”

“…Identical shapes for the TG curves of 1a and 1b are observed upon further heating up to 500 • C. In the case of the crystalline phase 1cr, the weight loss of 7.30% per chemical formula unit (calculated 7.40%) that corresponds to the loss of three and half water molecules is observed in the temperature range up to 160 • C. These results indicate that water molecules within 1a are significantly more loosely bounded than in 1cr. Then, higher thermal energy, in the range of 190 to 210 • C, leads to analogous well-defined exothermic weight loss, characteristic for cyanoiron(II) complexes [25], revealing their analogous composition to (TOXO) 2 [Fe(CN) 6 ], which continues to decompose on further heating. These gravimetric results show that the change in color between 1a and 1b is accompanied by extrication of eight water molecules per chemical formula unit.…”

Synthesis and characterization of Bi1−xNdxFeO3 (0 ≤ x ≤ 0.3) prepared by thermal decomposition of Bi1−xNdx[Fe(CN)6]·4H2O

“…The synthesis from the thermal decomposition of heteronuclear complexes has not been reported yet. The potentiality of this method to produce homogeneous powders with high surface area is due to the mixing of metal cations at the atomic level with the desired stoichiometry of the metals in the heteronuclear complex, allowing to obtain the oxides at lower temperatures than traditional methods [14,[17][18][19][20][21][22][23][24].…”