Aminoguanidinium(2+) Hexafluorozirconate Monohydrate: A Co-Product of Preparing the Ferroelectric Anhydrous Salt

Abstract

Preparation of anhydrous aminoguanidinium(2+) hexauorozirconate, CN 4 H 8 ZrF 6 , shown previously to satisfy the structural criteria for ferroelectricity [Abrahams et al. (1996). Acta Cryst. B52, 806±809], generally results in the co-formation of a series of related¯uorozirconates.

Crystal Structures and Raman Spectra of Imidazolium Poly[perfluorotitanate(IV)] Salts Containing the [TiF6]2–, ([Ti2F9]−)∞, and [Ti2F11]3– and the New [Ti4F20]4– and [Ti5F23]3– Anions

“…The first evidence for a tetramer comprised of four MF 6 octahedra sharing four vertices was provided by the 119 Sn and 19 F NMR spectra of “N 5 SnF 5 ” in a HF solution, which yielded the gross geometry of the [Sn 4 F 20 ] 4– anion . Two tetrameric perfluorotitanate salts, [Ti 4 F 18 ] 2– , and [Ti 4 F 19 ] 3– , and two tetrameric non-titanium compounds, [C 6 N 4 H 21 ] 2 [V 4 O 4 F 14 ]·3H 2 O and [CN 4 H 8 ] 4 [Zr 4 F 24 ]·4H 2 O, have been described in the literature. The [V 4 O 4 F 14 ] 6– anion is comprised of four VOF 5 octahedra sharing two vertices and two edges, whereas the [Zr 4 F 24 ] 8– anion is comprised of four ZrF 8 square antiprisms sharing four edges.…”

Prediction of new displacive ferroelectrics through systematic pseudosymmetry search. Results for materials with Pba2 and Pmc21 symmetry

“…Recent experimental results show that the room-temperature phases of K 3 Sb 5 O 14 (Hong, 1974) and (Ba 0X6 K 0X4 )BiO 2X23 (Shiyou et al, 1991) have symmetry Pbam and not Pba2. Further, the lower-symmetry phase of [C(NH 2 ) 2 (N 2 H 4 )]ZrF 6 has been recently redetermined to be P2 1 an (Ross et al, 1998).…”

Hydrothermal Preparation of Nickel(II)/Uranium(IV) Fluorides with One-, Two-, and Three-Dimensional Topologies

“…The sides of the columns are terminated by octahedral Ni(II) that occur as cis -[Ni(H 2 O) 4 F 2 ] polyhedra. The individual chains that edge share to form the columns of 1 are similar to the one-dimensional [MF 4/1 F 4/2 ] 4- (M = Zr, U) chains found in several inorganic and organically templated U(IV) and Zr(IV) fluorides. ,−

1 View of the zigzagging chains of edge-sharing dodecahedral [UF 8 ] units that are linked to form columns in Ni(H 2 O) 4 UF 6 ·1.5H 2 O ( 1 ). The periphery of these U(IV) fluoride columns are lined with cis -[Ni(H 2 O) 2 F 4 ] octahedra.

…”