Ion-Pairing\nStereodynamic Probes for Circular Dichroism\nChiral Sensing of Amines

Tris(2-pyridylmethyl)amine (<b>TPMA</b>) and tris(2-phenolmethyl)amine\n(<b>TPA</b>) metal complexes have been extensively used for\ncatalysis and molecular recognition applications. In particular, due\nto their ability to form stereodynamic complexes through the helical\narrangement of the ligand around the metal in a propeller shape, chiroptical\nsensing has been extensively investigated. In particular, the capability\nof the analyte, usually a Lewis base, to bind the metal complex has\nbeen the predominant recognition motif. Herein, we report the synthesis\nand application of a zinc <b>TPA</b>-based stereodynamic probe\nfor the sensing of chiral amines and amino-alcohols in which an ion-pair\ninteraction between the anionic metal complexes and the ammonium ions\nis responsible for the recognition.