This study focuses on exploring the solvation and lone pair effects on the second harmonic generation (SHG) of circular π-conjugated macrocycles, using density functional theory (DFT). SHG is a second-order nonlinear optical phenomenon with potential applications in photonics, biosensors, and microscopy. The ability of these macrocycles to generate second harmonic is crucial for their use in these emerging technologies.

The research has been carried out using DFT calculations, a computational tool that allows predicting the electronic and optical properties of molecules. Special attention has been paid to how the solvation environment (interaction with the solvent) and the presence of lone pairs of electrons influence the SHG efficiency. These factors are known to significantly modify the nonlinear optical response of molecular materials, making their understanding fundamental for the design of new compounds with improved properties.