Bismuth Cations: Fluoride Ion Abstraction, Isocyanide Coordination, and Impact of Steric Bulk on Lewis Acidity
Tobias Dunaj, Johannes Schwarzmann, Jacqueline Ramler, Andreas Stoy, Sascha Reith, Joel Nitzsche, Lena Völlinger, Carsten von Hänisch, Crispin Lichtenberg
Abstract
Abstract The molecular compound [BiDipp 2 (SbF 6 )], containing the bulky, donor‐free bismuth cation [BiDipp 2 ] + has been synthesized and fully characterized (Dipp=2,6‐ i Pr 2 ‐C 6 H 3 ). Using its methyl analog [BiMe 2 (SbF 6 )] as a second reference point, the impact of steric bulk on bismuth‐based Lewis acidity was investigated in a combined experimental (Gutmann‐Beckett and modified Gutmann‐Beckett methods) and theoretical approach (DFT calculations). Reactivity studies of the bismuth cations towards [PF 6 ] − and neutral Lewis bases such as isocyanides C≡NR’ revealed facile fluoride ion abstraction and straightforward Lewis pair formation, respectively. The first examples of compounds featuring bismuth‐bound isocyanides have been isolated and fully characterized.