Strukturen und thermische Zersetzung von enH2(H3O)[AlF6] und enH2[AlF5(H2O)]

Crystal structure of bis-(propane-1,3-diaminium) hexa-fluorido-aluminate di-aqua-tetra-fluorido-aluminate tetra-hydrate

In the crystal structure of bis­(propane-1,3-di­ammonium) hexa­fluorido­aluminate di­aqua­tetra­fluorido­aluminate tetra­hydrate, two different environments of the Al³⁺ cations are observed, namely, AlF₆ and AlF₄(H₂O)₂.

The title compound, (C₃H₁₂N₂)₂[AlF₆][AlF₄(H₂O)₂]·4H₂O, was obtained by a solvothermal method in ethanol as solvent and with aluminium hydroxide, HF and 1,3-di­amino­propane as educts. The asymmetric unit contains a quarter each of two crystallographically independent propane-1,3-di­ammonium dicat­ions, [AlF₆]³⁻ and [AlF₄(H₂O)₂]⁻ anions and four water mol­ecules. The cations, anions and three of the independent water mol­ecules are situated on special positions mm, while the fourth water mol­ecule is disordered about a mirror plane. In the crystal, inter­molecular N—H⋯F and O—H⋯F hydrogen bonds link the cations and anions into a three-dimensional framework with the voids filled by water mol­ecules, which generate O—H⋯O hydrogen bonds and further consolidate the packing.

Bis(propane-1,3-diaminium) hexa-fluoridoferrate(III) fluoride trihydrate

The asymmetric unit of the title iron hybrid fluoride, (C(3)H(12)N(2))(2)[FeF(6)]F·3H(2)O, contains two propane-1,3-diamin-ium [(H(2)dap)(2+)] cations, an octa-hedral [FeF(6)](3-) anion, an isolated F(-) anion and three water mol-ecules of solvation. Each [FeF(6)](3-) anion is surrounded by four separate hydrogen-bonded water mol-ecules in the equatorial sites and by five separate aminium cation donor groups. The axial F atoms are only involved in N-H⋯F hydrogen bonds, resulting in a three-dimensional structure.

A Ladderlike Chain Aluminum Fluoride ([Al2F8]2-)n with Edge-Sharing AlF6 Octahedra

A new aluminum fluoride, Al(2)F(8).2NC(5)H(6).C(6)H(3)(CO(2)H)(3), was synthesized under mild hydrothermal conditions (200 degrees C, 3 days) in the presence of 1,3,5-benzenetricarboxylic acid (btc) in pyridine/HF (pyr/HF) solvent. Its structure is characterized with single-crystal XRD analysis and high-resolution solid-state NMR. The inorganic framework consists of the corner- and edge-shared connections of AlF(6) octahedra. They are linked via a common edge and form a bioctahedral motif which is trans-connected through the corner-shared fluorine. It results in the formation of an original infinite double file of AlF(6) octahedra running along the a axis. A high-power decoupled MAS (27)Al{(19)F} Hahn echo NMR spectrum allowed us to distinguish the two crystallographic hexacoordinated Al sites. Four unresolved (19)F NMR signals are observed in the MAS spectra to account for the eight crystallographic fluorine atoms. Half of the terminal fluorine sites interact via strong hydrogen bonds with the ammonium groups of the pyridine moieties. The resulting mixed pyridine-fluoroaluminate chains are intercalated by the btc molecules which are hydrogen-bonded to the remaining free terminal fluoride anions through the protonated carboxylic acid function. The (1)H nuclei of both organic molecules are observed in the protonated form.