Chalcones belong to the flavonoids family and are natural compounds which show promising larvicidal property against Aedes aegypti larvae. Aiming to obtain a synthetic chalcone derivative with high larvicidal activity, herein, a bromochalcone derivative, namely (E)-3-(4-butylphenyl)-1-(4-bromophenyl)-prop-2-en-1-one (BBP), was designed, synthesized and extensively characterized by ¹H- and ¹³C- nuclear magnetic resonance (NMR), infrared (IR), Raman spectroscopy, mass spectrometry (MS), ultraviolet–visible spectroscopy (UV-Vis), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and X-ray diffraction. Further, the quantum mechanics calculations implemented at the B3LYP/6–311+G(d)* level of the theory indicate that the supramolecular arrangement was stabilized by C–H⋯O and edge-to-face C–H⋯π interactions. The EGAP calculated (3.97 eV) indicates a good reactivity value compared with other similar chalcone derivatives. Furthermore, the synthesized bromochalcone derivative shows promising larvicidal activity (mortality up to 80% at 57.6 mg·L⁻¹) against Ae. aegypti larvae.

The development of photoprotective agents presents a growing interest due to skin disorders, e.g., cancer. In order to obtain natural-based compounds with potential photoprotective activity, we promote the synthesis and extensive characterization of a butylchalcone derivative (E)-3-(4-butylphenyl)-1-(4-methylphenyl)-prop-2-en-1-one (BMP). Moreover, we carried out a comparative analysis of two chalcones bearing a methyl (BMP) and bromo (BBP) substituent groups (at para position), on respective electronic structures and supramolecular arrangement, using density functional theory (DFT). Through theoretical calculations carried out by DFT, it was possible to verify its antioxidant property by the mechanisms of free radical scavenging, H-atom transfer (HAT), and one-electron transfer (ET), and their stabilities. Finally, from the analysis of chalcone’s electronic transitions in the excited state calculated by the time-dependent (TD)-DFT method as well as UV-vis absorption spectra of the BMP and BBP (200–390 nm), it is possible to highlight their potential use as organic photoprotective agents.