Further Developments of Weakly Coordinating Cations: Fluorinated Bis(triarylphosphoranylidene)iminium Salts
Lisa Mann, Elisabeth Hornberger, Simon Steinhauer, Sebastian Riedel – 2018
So far unknown bis(triarylphosphoranylidene)iminium cations [PPN]⁺ with one fluorine atom in para ([PPN‐1F]⁺), two in meta ([PPN‐2F]⁺), or three in para and meta positions of the phenyl rings ([PPN‐3F]⁺) were obtained by a newly developed one‐pot reaction. These halogenated [PPN]⁺ cations were characterized by IR and Raman spectroscopy in comparison with quantum‐chemical calculations, ESI⁺ mass spectrometry, NMR spectroscopy, and single‐crystal X‐ray diffraction. To assess their quality as weakly coordinating cations and the associated ability to stabilize labile anions, the electrostatic potential and fluoride‐ion affinity were calculated and compared with those of the unsubstituted and so far unknown perfluorinated [PPN‐5F]⁺ cations.