The author of 《An Experimental Acidity Scale for Intramolecularly Stabilized Silyl Lewis Acids》 were Kuenzler, Sandra; Rathjen, Saskia; Merk, Anastasia; Schmidtmann, Marc; Mueller, Thomas. And the article was published in Chemistry – A European Journal in 2019. HPLC of Formula: 1194-02-1 The author mentioned the following in the article:
A new NMR-based Lewis acidity scale is suggested and its application is demonstrated for a family of silyl Lewis acids. The reaction of p-fluorobenzonitrile (FBN) with silyl cations that are internally stabilized by interaction with a remote chalcogenyl or halogen donor yields silylated nitrilium ions with the silicon atom in a trigonal bipyramidal coordination environment. The 19F NMR chem. shifts and the 1J(CF) coupling constants of these nitrilium ions vary in a predictable manner with the donor capability of the stabilizing group. The spectroscopic parameters are suitable probes for scaling the acidity of Lewis acids. These new probes allow for the discrimination between very similar Lewis acids, which is not possible with conventional NMR tests, such as the well-established Gutmann-Beckett method. In the experiment, the researchers used 4-Fluorobenzonitrile(cas: 1194-02-1HPLC of Formula: 1194-02-1)
4-Fluorobenzonitrile(cas: 1194-02-1) is used as chemical intermediate, solvent for perfumes and pharmaceuticals, stabilizer for chlorinated solvents, HPLC analysis, catalyst and component of transition-metal complex catalysts.HPLC of Formula: 1194-02-1
Referemce:
Nitrile – Wikipedia,
Nitriles – Chemistry LibreTexts