Darstellung und Kristallstruktur von Diammonium‐heptachloropentaoxotriniobat(V) (NH₄)₂[Nb₃O₅Cl₇]

Abstract

Man erhält (NH4)2[Nb3O5Cl7] in kristalliner Form in Quarzglasampullen aus NbCl5, NH4Cl und As2O3 bei 1050 K. Die Kristalle sind farblos manchmal blaßblau. (NH4)2[Nb3O5Cl7] kristallisiert bei 293 K monoklin in der Raumgruppe C2/c mit Z = 4 und den Gitterkonstanten a = 1680,6(8) pm, b = 886,6(1) pm, c = 1104,3(5) pm und β = 111,35(2)° Die Struktur besteht aus [(Nb3O5Cl7)2−] ∞2‐Schichten in denen die Oktaederbasisflächen über Ecken verknüpft sind. Die Struktur des Polyanions zeigt eine neuartige Oktaederverknüpfung für eine MX4‐Schichtstruktur. Zwischen diesen Schichten befinden sich die Ammoniumionen.

Crystal Structure and Magnetic Properties of Bi(Bi9)[NbCl6]3, a New Member of the Structure Family Bi(Bi9)[MX6]3, and the Crystal Structure of Bi8[Ta2O2Br7]2

“…After Te 4 [Ta 2 OBr 10 ]18 and (NH 4 ) 2 [Ta 3 O 5 Br 7 ],36 [Ta 2 O 2 Br 7 ] − is only the third crystallographically characterized bromooxotantalate( V ) reported. In contrast to [Ta 2 OBr 10 ] 2− (Te 4 [Nb 2 OCl 10 ]37) and [Ta 3 O 5 Br 7 ] 2− {(NH 4 ) 2 [Nb 3 O 5 Cl 7 ]38} no isostructural Nb/Cl analogue is known for [Ta 2 O 2 Br 7 ] − . This anion consists of two symmetrically independent TaO 2 Br 4 octahedra.…”

On Oxohalogeno Niobates(V) M2[Nb3O5X7] (M = NH4, K, Rb, Cs; X = Cl, Br) – New Members of a Compound Family with a Layered Structure

“…A grinded sample of the regulus was filled in a thinwalled glass capillary of 0.1 mm diameter. The X-ray powder diffractogram (STOE StadiP diffractometer, linear position sensitive detector, Debye-Scherrer geometry, Cu-KͰ 1 radiation, external Si standard) showed reflections attribu- 6 ]. All these compounds were identified by Xray single crystal determinations [14].…”