Molecular Sensing of Chiral Carboxylic Acid Enantiomers Using CD Inductions in the Visible Light Region

The reaction between a chiral carboxylic acid molecule and 1,1′-bis(diphenylphosphino)ferrocenepalladium dichloride in the presence of a mild base generates a chiroptically active metal complex displaying strong circular dichroism (CD) signals in the visible light region, a highly sought-after goal in the optical sensing realm. The molecular recognition process is complete within a few minutes and can be used for fast chiroptical determination of the enantiomeric composition and concentration of carboxylic acid samples. This method is operationally simple and broadly applicable to a large variety of structures including important drugs, natural products, amino acids, and hydroxy acids. All components needed are commercially available, and this optical sensing assay can be readily adapted by any laboratory interested in chirality analysis and high-throughput experimentation.