In this work, we have studied both experimentally and theoretically the oxybutynin chiral discrimination. According to the main results, the enantioseparation of oxybutynin was efficiently achieved by high performance liquid chromatography in normal phase using the Chiralpak® AD column, which has amylose tris (3,5‐dimethylphenylcarbamate) as a chiral selector. The energetic and structural parameters obtained via density functional theory calculations pointed out the chiral discrimination as well as the enantiomeric elution order of oxybutynin, thus explaining, at molecular level, the experimental data. Finally, the strength of the hydrogen bonds played a key role in the discrimination between the oxybutynin diastereomeric complexes formed.

Thiacloprid (TCP) is a synthetic insecticide, belonging to the class of neonicotinoids (NNCs), which present potential damages to the environment, biodiversity and human health, being necessary its constant monitoring. In this sense, molecularly imprinted polymers (MIPs) have been shown as an excellent alternative for the separation science, since they can recognize molecularly and selectively the analyte in various types of complex sample, such as food, soil, etc., thus contributing to its efficient extraction. In the present work, we have investigated, through DFT calculations, the mechanism of formation of a MIP for the TCP. As main result we obtained the following theoretical protocol for the MIP synthesis: 2-(trifluoromethyl) aryl acid (TFMAA) as FM (functional monomers), in 1:3 stoichiometry, and toluene as the solvent. This theoretical protocol showed the most favorable stabilization energies for the pre-polymerization complexes formed. In addition, it has been shown that the establishment of hydrogen bonds between the TCP and FM play a fundamental role in the stability of the complexes formed. We consider this work quite relevant since it can be used by experimentalists in order to reach an efficient MIP synthesis for TCP.