Towards Laser Desorption CD-REMPI

Abstract

Laser-induced desorption provides a powerful route for transferring involatile organic molecules from condensed phases into the gas phase, enabling spectroscopic interrogation under controlled conditions. In this work, we present a combined experimental platform integrating matrix-assisted laser desorption (MALDI) with resonance-enhanced multiphoton ionization (REMPI), with the aim of probing chiral organic materials. The apparatus enables the entrainment of desorbed molecules into a supersonic molecular beam and their subsequent detection via time-of-flight mass spectrometry. Benchmark measurements using (R)-3-methylcyclopentanone (3-MCP) demonstrate robust REMPI and circular dichroism REMPI (CD-REMPI) performance, confirming the system’s sensitivity to chiroptical signals. Extending this approach, we show that BINOL, a prototypical chiral organic material, can be desorbed from a carbon matrix and detected in the gas phase with sufficient stability to acquire REMPI spectra. The observed spectral broadening reflects incomplete cooling of the desorbed molecules and highlights the non-equilibrium nature of the desorption process. While chiroptical detection of desorbed BINOL remains limited, the results establish a functional platform for studying laser-induced desorption of chiral materials. The approach provides a foundation for future investigations of matrix-free and enantiospecific desorption processes, which are of significant relevance for nanoscale chirality and surface science.