Synthesis and Characterization of Fluorinated Metal Arsenates with a Layer Structure:  (C₄H₁₂N₂)_1.5[M₃F₅(HAsO₄)₂(AsO₄)] (M = Fe, Ga)

Abstract

Two fluorinated metal arsenates, (C(4)H(12)N(2))(1.5)[M(3)F(5)(HAsO(4))(2)(AsO(4))] (M = Fe, Ga), have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction, magnetic susceptibility, Mössbauer spectroscopy, and (71)Ga NMR spectroscopy. The two compounds are isostructural and crystallize in the monoclinic space group P2(1)/c (No. 14) with a = 8.394(1) A, b = 21.992(3) A, c = 10.847(1) A, beta = 96.188(2) degrees, and Z = 4 for the Fe compound, and a = 8.398(1) A, b = 21.730(3) A, c = 10.679(1) A, beta = 95.318(2) degrees, and Z = 4 for the Ga compound. The structure consists of infinite chains of corner-sharing MX(6) (X = O, F) octahedra and dimers of edge-sharing MO(3)F(3) octahedra, which are linked into two-dimensional sheets through arsenate tetrahedra with diprotonated piperazinium cations between the sheets. Magnetic susceptibility and Mössbauer spectroscopy confirm the presence of Fe(III). The (71)Ga MAS NMR spectrum clearly shows a line shape consisting of three components, corresponding to three crystallographically distinct Ga sites.

A Reactive Intermediate in the Synthesis of Iron Arsenates: Synthesis of the First One-Dimensional Iron Arsenate Oxalate and Its Transformation into Two- and Three-Dimensional Iron Arsenates

“…The structure of II is similar to the iron–arsenate structure reported recently by Luo et al,11 which consists of infinite chains of corner‐sharing FeX 6 (X=O, F) octahedra and dimers of edge‐sharing FeO 3 F 3 octahedra, linked into 2D sheets through arsenate tetrahedra (Figure 1 b). The piperazinium cations occupy interlamellar space and interact with the framework through N−H⋅⋅⋅O hydrogen bonds.…”

Offene Gerüststrukturen von Übergangsmetallen

“…Dabei ragen die Liganden 2,2′‐bpy und 1,10‐phen nach oben und unten aus den Schichten heraus und beteiligen sich an π‐π‐Wechselwirkungen, während der Ligand 4,4′‐bpy in [(VO 2 ) 2 (4,4′‐bpy) 0.5 (4,4′‐Hbpy)(AsO 4 )]⋅H 2 O die eindimensionalen Vanadylarsenatketten zu den Schichten verbindet 114b. In [C 4 N 2 H 12 ] 1.5 [Fe 3 F 5 (HAsO 4 ) 2 (AsO 4 )] sind Fe‐X‐Fe‐Endlosketten aus eckenverknüpften FeX 6 ‐Oktaedern (X=O, F) durch die SBUs‐4 zu einer Schichtstruktur verbunden 115b…”

Formation of a 3D Porous Ferric Arsenate Containing Novel Cubane-like Fe4F4 Building Units

“…Little work, however, has been carried out on the arsenate as compared to the phosphate. To date, only several arsenates of aluminum, gallium, molybdenum, vanadium, zinc, and iron have been reported in the literature, though arsenic belongs to the same group as phosphorus. Open-framework structures based on arsenates are beginning to attract the attention of synthetic chemists because the larger size of As 5+ (0.335 Å) compared to P 5+ (0.17 Å) may give rise to novel architectures .…”