Stabilization of classical (anhydrous) Brønsted acids by the Lewis acids B(C6F5)3 and [Me3Si]+

• Applicant: Professor Dr. Axel Schulz
• Subject Area: Inorganic Molecular Chemistry - Synthesis and Characterisation
• Term: since 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 321319519

The aim of the research project is the synthesis and adduct stabilization of simple (mostly labile) planar, resonance-stabilized pseudohalogen acids (H-X, X = C(CN)3-, H(CN)NO-, H(CN)NO2-, HC(NO)2-, C(NO2)3-, NC-N-CN-, NC-N-NO2-, etc.) as well as their silylated homologues (Me3Si-X), which have not yet been investigated in the first period. Adduct stabilization is to be carried out on the one hand by the bulky, neutral Lewis acid B(C6F5)3 and on the other hand by the very strong cationic Lewis acid [Me3Si]+, so that in the first case neutral acid adducts are formed (H-X-B(C6F5)3 or Me3Si-X-B(C6F5)3), while adduct formation with silylium ions leads to cations of the type [H-X-SiMe3]+ or [Me3Si-X-SiMe3]+. This approach allows the systematic investigation of the stability, structure, and bonding depending on the steric hindrance (H vs. Me3Si or B(C6F5)3 vs. [Me3Si]+) as well as the charge of the adduct system (neutral vs. cationic). Furthermore, we would like to use the anions activated by the strong electron pull in synthetic chemistry, e.g., in electrophilic aromatic substitutions. In summary, we would like to show that adduct formation can be used to stabilize especially the very labile planar resonance-stabilized pseudohaloacids and thus make them accessible in substance for subsequent reactions.

• DFG Programme: Research Grants