Self-referencing circular dichroism ion yield measurements for improved statistics using femtosecond laser pulses.

C Witte,S Vasudevan,T Ring,H Braun,A Senftleben,H Lee,N Ladda,S T Ranecky,S Das,T Baumert

doi:10.1063/5.0036344

C Witte, S Vasudevan + Show 8 more

Open Access

https://doi.org/10.1063/5.0036344

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Journal: The Review of scientific instruments	Publication Date: Mar 1, 2021
Citations: 6	License type: cc-by

Affiliation: University of Kassel

Abstract

The combination of circular dichroism with laser mass spectrometry via the measurement of ion yields is a powerful tool in chiral recognition, but the measured anisotropies are generally weak. The method presented in this contribution reduces the measurement error significantly. A common path optical setup generates a pair of counter-rotating laser foci in the interaction region of a time-of-flight spectrometer. As the space focus condition is fulfilled for both foci individually, this becomes a twin-peak ion source with well separated and sufficiently resolved mass peaks. The individual control of polarization allows for in situ correction of experimental fluctuations measuring circular dichroism. Our robust optical setup produces reliable and reproducible results and is applicable for dispersion sensitive femtosecond laser pulses. In this contribution, we use 3-methyl-cyclopentanone as a prototype molecule to illustrate the evaluation procedure and the measurement principle.

Highlights

Optical activity phenomena rely on the helicity-specific response of a substance to circularly polarized light.1 In this way, the enantiomers of chiral molecules can be distinguished via light–matter interaction
The combination of circular dichroism with laser mass spectrometry via the measurement of ion yields is a powerful tool in chiral recognition, but the measured anisotropies are generally weak
The combination with time-of-flight laser mass spectrometry (LaMS) allows for the detection of the circular dichroism (CD) of parent and fragment ions, and measurements have been reported on a variety of chiral molecules

Summary

Introduction

Optical activity phenomena rely on the helicity-specific response of a substance to circularly polarized (cpl) light.1 In this way, the enantiomers of chiral molecules can be distinguished via light–matter interaction. The combination of circular dichroism with laser mass spectrometry via the measurement of ion yields is a powerful tool in chiral recognition, but the measured anisotropies are generally weak.

Results

Conclusion