Triflimidic

Triflimidic is a term used to describe compounds that contain the bis(trifluoromethylsulfonyl)imide moiety, commonly abbreviated as NTf2. The word is often applied to the triflimide acid and to salts in which the NTf2− anion pairs with a cation. The NTf2− anion is a large, highly delocalized, non-coordinating anion that imparts notable stability and inertness to its salts.

The triflimide concept is central in areas such as catalysis and ionic liquids. Salts and ionic liquids bearing the NTf2− anion are prized for their low basicity, high thermal stability, and weak coordinating behavior, which can help stabilize reactive cations and improve catalytic performance. The triflimide-based ionic liquids, including examples like EMIMNTf2, are widely used as solvents and electrolytes because of their chemical robustness and broad electrochemical windows.

Triflimide acid, HNTf2, is among the strongest known Brønsted superacids and is used to generate highly acidic media for challenging transformations. In practice, HNTf2 is typically employed in stoichiometric or catalytic protocols to achieve extreme acidity while maintaining relatively non-nucleophilic conditions due to the weakly coordinating NTf2− anion.

Preparation and handling of triflimidic compounds focus on maintaining anhydrous conditions given the moisture sensitivity of the NTf2− system and the corrosive nature of the related acid. These materials are typically handled under appropriate dry and inert atmosphere conditions, with careful disposal to avoid environmental and health hazards.