Estudo teórico das propriedades estruturais, eletrônicas e espectroscópicas da molécula Timol em fase gasosa e solvente

Abstract

Thymol belongs to the terpene family. The aromatic monoterpenoid molecule is the main constituent of several essential oils extracted from aromatic plants. Thymol is reported to have strong anti-inflammatory, anti-oxidant, antibacterial, antifungal, anticarcinogenic activities. Due to its broad spectrum os action, currently, it is among the most studied essential oil constituents. Thymol is the most potent of the phenols, abundantly found in the essential oil of Lippia menosides Cham. (Verbanaceae), the rosemary-pepper ", a typical specimen of the Brazilian Northeast. In this work, performed a detailed characterization of the thymol molecule by analyzing its structural, electronic and spectroscopic properties, both in gas and in solution, with methanol as solvent, using quantum calculations based on Density Functional Theory (DFT). Two quantum chemical models were used to perform the calculations: B3LYP / 6-31 ++ G (d, p) and B3LYP / augcc-pVDZ. The presence of the solvent was treated with the autoconsistent reaction field method (SCRF) using, in particular, the Continuous Polarizable Model (PCM). For the study of UV-Vis spectra we used two theoretical methods: Time Dependent Density Theory (TD-DFT) and the semi-empirical method ZINDO. To complement our study, we collaborated with Nanostructured Polymers Laboratory (NANOPOL) of UFAM for experimental measurements of the UV-Vis spectrum of thymol in methanol. Between the two methods, the ZINDO result is comparatively better than TDDFT.