Noncovalent Interactions in Halogenated Pyridinium Salts of the Weakly Coordinating Anion [Al(OTeF5 )4 ].

The synthesis and the first structural characterization of the halogenated pyridinium salts [C5 F5 NH]+ , [C5 F4 ClNH]+ , [(C5 F5 N)2 H]+ , [(C5 Cl5 N)2 H]+ of the weakly coordinating anion (WCA) [Al(OTeF5 )4 ]- , showing noncovalent interactions in the solid state, are presented. The salts were characterized by the multinuclear NMR and IR spectroscopy as well as X-ray diffraction. Hirshfeld surface analysis and solid state structures reveal various intermolecular anion-π and σ-hole interactions between the corresponding halogenated pyridinium cations and the anion [Al(OTeF5 )4 ]- .