Quantitative Measure for the “Nakedness” of Fluoride Ion Sources

Abstract

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B‐Octamethyl‐[12]Mercuracarborand‐4 as Host for “Naked” Fluoride Ions

“…5 The increased reactivity was explained by the “cesium effect”4 in which the reactivity of the fluoride ion increases with the increasing size of the counterion, thereby providing more‐exposed fluoride ions and resulting as well in their increased solubility in aprotic organic solvents. More recently, an in situ method for the preparation of anhydrous fluoride‐ion solutions,6 the solvent dependency of the 19 F NMR chemical shifts of the fluoride ion,7 and a quantitative measure for the donor abilities, or “nakedness”, of fluoride ion donors8 have been reported.…”

Simple Access to the Non‐Oxidizing Lewis Superacid PhF→Al(ORF)3 (RF=C(CF3)3)

“…Lewis acidity, in this case the FIA, can be assessed by several means. [4][5][6]13] However, the simplest and most general access to reliable FIA values now comprises the use of quantum chemical calculations in isodesmic reactions. [5] Table 1 shows the calculated FIAs of a representative set of strong neutral Lewis acids.…”

Ein leichter Zugang zur nicht‐oxidierenden Lewis‐Supersäure PhF→Al(ORF)3 (RF=C(CF3)3)

“…Prinzipiell kann die Lewis-Acidität, hier die FIA, auf unterschiedliche Weise bestimmt werden. [4][5][6]13] Die einfachste und für jedermann zugängliche Methode der Bestimmung verlässlicher FIA-Werte stützt sich auf quantenchemische Berechnungen isodesmischer Reaktionen. [5] Tabelle 1 zeigt die berechneten FIA-Werte einer repräsentativen Auswahl sehr starker neutraler Lewis-Säuren.…”