Diprotonated Tetra(2‐pyridyl)pyrazine and its Chemical Mimesis due to Different Hydrogen Bridges

Abstract

There are two possible sites for the protons in the title compound. For steric reasons the structure in which the protons each interact with three nitrogen atoms is rejected in favor of the structure depicted on the right. The counterion BPh is essential; when Cl− is the counterion, drastic structural changes are induced in the dication. This phenomenon may also be significant in biologically important structures (nitrogen bases!).