Kristallstrukturanalyse und Natriumionenleitung von wasserfreiem α‐Natriumtrifluoromethylsulfonat

Abstract

Der Einkristallstrukturanalyse bei —173 °C zufolge kristallisiert α‐NaSO3CF3 triklin in der Raumgruppe P1¯ mit den Gitterparametern a = 9, 6592(11), b = 11, 1752(12), c = 11, 2768(12) Å, α = 101, 878(2)°, β = 105, 292(2)°, γ = 110, 501(3)°, bei Raumtemperatur (22 °C) ergeben sich die Werte a = 9, 81304(18), b = 11, 3179(2), c = 11, 5910(2) Å, α = 102, 066(2)°, β = 105, 634(2)°, γ = 110, 205(2)° (Synchrotron‐Pulverdaten). In der Kristallstruktur liegen Doppelschichten aus Triflatanionen vor, in denen die unpolaren CF3‐Gruppen einander zugewandt sind. Die Natriumatome besetzen fünf verschiedene kristallographische Lagen. α‐NaSO3CF3 ist ein fester Elektrolyt, dessen spezifische Leitfähigkeit im Bereich von 1, 75·10—8 Ω—1cm—1 bei 140 °C bis 8, 78·10—6 Ω—1cm—1 bei 237 °C liegt.

Crystal Structure and Ionic Conductivity of Cesium Trifluoromethyl Sulfonate, CsSO3CF3

“…The crystal structure of lithium triflate was firstly solved by X-ray powder diffraction [18] and later confirmed by single crystal structure determination [19]. The ionic conductivities and crystal structures of sodium triflate [20] and potassium triflate [21] were investigated. In addition, the cationic conductivities of lithium triflate and rubidium triflate were reported [22].…”

Twinned α-LiRb2(CF3SO3)3

“…In the structure of -LiRb 2 (SO 3 CF 3 ) 3 , three crystallographically independent tri¯ate ions can be distinguished. Their conformation is staggered and the observed bond lengths and angles are comparable with those in -LiSO 3 CF 3 (Bolte & Lerner, 2001), -NaSO 3 CF 3 (So®na et al, 2003), the low-and room-temperature modi®cations of NaSO 3 CF 3 ÁH 2 O (Korus & Jansen, 1997), NaSO 3 CF 3 Á3HSO 3 CF 3 (Korus & Jansen, 1998) and RT-KSO 3 CF 3 (Korus & Jansen, 2001).…”

“…Alkali metal salts of the triuoromethanesulfonate (tri¯ate) ion belong to these so-called rotator phases. Due to their interesting properties, the ionic conductivities and crystal structures of, for example, -LiSO 3 CF 3 (Tremayne et al, 1992;Bolte & Lerner, 2001), -NaSO 3 CF 3 (So®na et al, 2003) and RT-KSO 3 CF 3 (Korus & Jansen, 2001) have been studied in detail. Furthermore, mixed alkali tri¯ates offer the possibility of exploring the`mixed cation effect', which can be observed in ion-conducting systems containing more than one mobile cation (Yanija & Secco, 1995).…”

Cation Mobility and Anion Reorientation in Sodium Trifluoromethyl Sulfonate

“…[16] A view of the structure is shown in Figure 1 a. Similar to the lithium [17,18] and cesium trifluoromethyl sulfonates, the triflate anions are arranged in double layers with the lipophilic CF 3 groups pointing towards one another.…”