Series of Protonated Nitrogen Bases with a Weakly Coordinating Counteranion: Observation of the 14N-1H Spin-Spin Coupling

Abstract

A distinguished triplet splitting pattern for the 14N-1H couplings in the proton signals of a series of protonated nitrogen bases─aliphatic and aromatic amines, as well as pyridines─with the weakly coordinating tetrakis(pentafluorophenyl)borate anion, [B(C6F5)4]−, is observed for the first time in nonaqueous media at room temperature. The effects of ion pairing, solvent parameters, and correlation between the δH1JNH, and pKa values are reported.