Kristallstrukturanalyse von (NH₄)₂NaInF₆

Abstract

(NH4)2NaInF6 wurde auf einem neuen Wege aus In2O3, NaF und NH4F hergestellt und die Kristallstruktur aufgeklärt (Fm3m, a = 8,6675(3) Å, Z = 4, 4 106 Reflexe, R = 0,007). Es liegt eine Elpasolith‐Variante vor, die Ammoniumionen sind geordnet.

Thermodynamic properties andp-Tphase diagrams of (NH4)3M3+F6cryolites (M3+: Ga, Sc)

“…The orientational disorder of fluorine octahedra in a cubic phase was considered as connected with 192l position of fluorine atoms with a respective occupancy fraction of 1/8. Of two ammonium ions occupying different sites 8c and 4b only the latter is disordered, having two distinct orientations [5,17]. Thus the total entropy connected with structural distortions due to the ionic ordering is given by the sum of contributions from the ammonium and hexafluorometallate(III) ions: S = R(ln 2 + ln 8) = 2.77R.…”

Solvothermal indium fluoride chemistry: Syntheses and crystal structures of K5In3F14, β-(NH4)3InF6 and [NH4]3[C6H21N4]2[In4F21]

“…3). The closest analogue to 2 which has been structurally characterised is (NH 4 ) 2 NaInF 6 [28]. This is reported to adopt the 'parent' ordered double perovskite structure type (cubic, Fm-3m, a $2 a p ), albeit with ordering of the NH þ 4 groups.…”

Diammonium sodium hexafluoroaluminate, (NH4)2NaAlF6

“…A considerable number of complex fluoride compounds have been characterized in the past decades, with general formula A 2 BCF 6 (A = Na, K, NH 4 , Rb, Cs, Tl; B = Li, Na, K, Rb, Cs, Tl; C = Al, Ni, Co, Cr, Ga, V, Fe, Mn, Ti, Sc, In, Yb, Tl, Tm, Er, Y, Ho, Dy, Tb, Gd, Eu, Sm, Ce, Bi). To date, only one ammonium-based compound has been reported, namely (NH 4 ) 2 NaInF 6 (Roloff et al, 1995). We describe here the isotypic aluminium analogue, (NH 4 ) 2 NaAlF 6 ( Fig.…”