Clusters of chiral molecules in the isolated state

Chirality, a fundamental property present across different scales in our world, remains a captivating area of exploration. The origins of chirality and the intricate chemical pathways leading to the formation of the first replicable homochiral system are subjects of ongoing studies. This paper, dedicated to the late Prof Anna Giardini, unravels insights into chiral discrimination effects through Resonant Two-Photon Ionization (R2PI) spectroscopy on gas-phase intermolecular complexes. Using theoretical ab-initio calculations, and a range of resonant multiphoton spectroscopic techniques, this study reports on key aspects of chirality. This involves the application of One-color R2PI Spectroscopy, where diastereomeric complexes formed by non-covalent interactions between enantiomers of chiral solvent and a chiral chromophore are discerned. Moving on, Two-color R2PI Spectroscopy is discussed as a tool to measure binding energy differences between homochiral and heterochiral adducts. After which the study of Reaction Thresholds by Two-color R2PI is reported. Here, the impact of asymmetric microsolvation on the photodissociation of Cα-Cβ bonds is explored. This sheds light on how solvent molecules influence activation energies in these processes. Lastly, the investigation into One-color R2PI and IR-R2PI focuses on the effect of fluorine substitution on chiral recognition. The interplay of CH···π, OH···π, and CH···F interactions is analyzed, highlighting the specific molecular interactions crucial in chiral discrimination. This comprehensive exploration underscores the intricate molecular mechanisms governing chiral recognition and enantioselectivity, emphasizing the lasting impact of Prof Anna Giardini’s pioneering work in this field.