Diastereoselective supramolecular ion-pairing between the TRISPHAT anion and pro-chiral heptamethine cyanine dyes

Abstract

The supramolecular interactions between enantiopure TRISPHAT anion (tris(tetrachlorobenzenediolato)phosphate) and various non-chiral or pro-chiral heptamethine cyanine cations have been studied in the solid state by X-ray diffraction and in solution by NMR spectroscopy. The presence of the conformationally restricted tert-butyl functionalized cyclohexenyl moieties is responsible for the asymmetric shape interaction between the two ions revealing the chirality of the molecule. On the other hand, the strength of this interaction is controlled by the nature of the distal substituents.