A conformationally persistent pseudo-bicyclic guanidinium for anion coordination as stabilized by dual intramolecular hydrogen bonds

摘要

The first example of a pseudo-bicyclic guanidinium ligand is reported. When bound to an anion, the N,N'-bis(2-pyridyl)guanidinium cation persistently adopts the planar alpha,alpha conformation featuring intramolecular N center dot center dot center dot H-N-H center dot center dot center dot N hydrogen bonds in the solid state, which facilitates crystallization of sulphate from aqueous mixtures of anions.