Related Experiment Video
Updated: Dec 19, 2025

Coulomb Explosion Imaging as a Tool to Distinguish Between Stereoisomers
Published on: August 18, 2017
Distinguishing Enantiomers by Tip-Enhanced Raman Scattering: Chemically Modified Silver Tip with an Asymmetric Atomic
Thanyada Sukmanee1,2,3, Kanet Wongravee2,3, Yasutaka Kitahama1
1Department of Chemistry, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo, 669-1337, Japan.
Abstract:
Discrimination between enantiomers is achieved by tip-enhanced Raman scattering (TERS) using a silver tip that is chemically modified by an achiral para-mercaptopyridine (pMPY) probe molecule. Differences in the relative intensities of the pMPY spectra were monitored for three pairs of enantiomers containing hydroxy (-OH) and/or amino (-NH2 ) groups. The N: or N+ -H functionality of the pMPY-modified tip participates in hydrogen-bond interactions with a particular molecular orientation of each chiral isomer. The asymmetric arrangement of silver atoms at the apex of the tip induces an asymmetric electric field, which causes the tip to become a chiral center. Differences in the charge-transfer (CT) states of the metal-achiral probe system in conjunction with the asymmetric electric field produce different enhancements in the Raman signals of the two enantiomers. The near-field effect of the asymmetric electric field, which depends on the number of analyte functional groups capable of hydrogen-bond formation, improves the degree of discrimination.
More Related Videos
Related Concept Videos
Chirality at Nitrogen, Phosphorus, and Sulfur
A consequence of chirality is the need for enantiomeric resolution. While this is theoretically possible for all...
Properties of Enantiomers and Optical Activity
Naming Enantiomers
Racemic Mixtures and the Resolution of Enantiomers
¹H NMR Chemical Shift Equivalence: Enantiotopic and Diastereotopic Protons
In chiral compounds such as 2-butanol, replacing the methylene hydrogens at C3 produces a pair of...
Prochirality

