Optical Terpene and Terpenoid Sensing: Chiral Recognition, Determination of Enantiomeric Composition and Total Concentration Analysis with Late Transition Metal Complexes

Abstract

Quantitative chirality sensing of terpenes and terpenoids exhibiting a single double bond as the only functional group, such as α-pinene, β-pinene and camphene, or two alkene moieties like limonene, valencene and β-caryophyllene is among the most difficult molecular recognition tasks. In this work, a fast chiroptical sensing method that accomplishes determination of the enantiomeric excess and overall amount of a large variety of terpenes and terpenoids using readily available phosphine derived late transition metal complexes is presented. The terpene coordination is complete within 10 minutes and coincides with spontaneous induction of strong CD signals at long wavelengths and distinct UV changes which together allow accurate ee and concentration quantification.