A theoretical study on the gas-phase protonation of pyridine and phosphinine derivatives.

In this paper, we study the protonation of pyridine and phosphinine derivatives. In particular, the geometries, the amount of charge transfer, and the nature of the created N-H and P-H bonds are discussed, underlying the fundamental differences between the phosphorus and the nitrogen atoms as proton acceptors. Conceptual density functional theory and Bader's quantum theory of atoms-in-molecules are notably used to rationalize these trends and to predict the overall energies of these prototype gas-phase acid-base reactions.