Floridcarbonate der Alkalimetalle

Abstract

Fluoridcarbonate der Alkalimetalle A3(CO3)F bzw. A2A ′(CO3)F mit A,A′ = K, Rb, Cs wurden durch Festköperreaktionen aus entsprechenden Alkalimetallfluoriden und ‐carbonaten dargestellt. Sei kristallisieren isotyp mit K3(CO3)F. Die Gitterkonstanten von K2Rb(Co3)F, KRb2(CO3)F und CsRb2(CO3)F wurden mittels Röntgenpulvertechniken bestimmt und verfeinert. Lückenlose Mischkristallbildung wurde für das System K3(CO3)F/Rb3(CO3)F nachgewiesen. Die Kristallstrukturen von K2Rb(CO3)F und KRb2(CO3) wurden mit Einkristalldaten verfeinert. für K3(CO3)F und Rb3(CO3)F wurden die Raman‐ und IR‐Spektren auf der Basis der Faktorgruppennäherung interpretiert.

Natural and Synthetic Fluoride Carbonates

“…Finally, the synthesis of one fluoride carbonate series, A 2 A′-(CO 3 )F (A, A′ ) K, Rb, Cs), was achieved by solid-state synthesis. 12,13 Since then, numerous fluoride carbonates have been crystallized in subcritical and supercritical hydrothermal conditions, while only one phase, KCa(CO 3 )F, was synthesized by solid-state reaction. 14,15 Several new structural rare earth families, together with the first 3d transition metal compounds, have been substantiated; 16,17 the results of these investigations are reported in Table 2.…”

“…A lower density of carbonate groups is also found in alkaline fluoride carbonates A 3 (CO 3 )F (A ) K, Rb, or Tl). 12,13,59 Two out of three positions of a dense arrangement are replaced by one fluoride anion in B ( 2 / 3 , 1 / 3 ) and by three cations centered around C ( 1 / 3 , 2 / 3 ) (Figure 11).…”

“…Later, a crystal of Pb 2 (CO 3 )F 2 was obtained by chance by B. Aurivillius from a hydrothermal experiment at 180 °C. Finally, the synthesis of one fluoride carbonate series, A 2 A‘(CO 3 )F (A, A‘ = K, Rb, Cs), was achieved by solid-state synthesis. , …”