Microwave Three-Wave Mixing Spectroscopy of Chiral Molecules in Weakly Bound Complexes

[Image: see text] Since the first experimental implementation in 2013, microwave three-wave mixing has emerged as a robust spectroscopic approach for analyzing and controlling chiral molecules in the gas phase. This resonant, coherent, and nonlinear technique is based on the three-dimensional light–matter interaction in the electric dipole approximation, allowing for isomer- and conformer-selective chiral analysis with high resolution. Here we demonstrate the utility of microwave three-wave mixing for analyzing a molecular complex, limonene–H(2)O, which serves as a compelling example of addressing its potential to improve the chiral sensitivity for only weakly polar chiral molecules. The use of molecular complexes can also extend the applicability of microwave three-wave mixing to chiral systems that are not in the C(1) point group.