Propriedades estruturais, eletrônicas e ópticas do cristal do -α-pineno: uma abordagem DFT

Abstract

The α-Pinene is a secondary metabolite, belonging to the class of bicyclic monoterpenes, used in different industrial processes. The general objective of this study was to obtain the structural, electronic and optical properties of the α-Pinene crystal. In this work, we investigated the organic crystal (1S)-(-)-α-Pinene, an isomer of αPinene, which is made up of 4 molecules of α-Pinene (C10H16) in its unit cell. In this investigation, the structural and electronic properties of the (1S)-(-)-α-Pinene isomer crystal were obtained, as well as its light absorption spectrum. The results of this research showed that the structural properties obtained at the theoretical level are in good agreement with the experimental data. The electronic band structures obtained through the LDA and GGA (PBE) calculations, both indicate that the most relevant electronic transitions occur along the  to Y paths with values in the indirect gaps around 3.5812 𝑒𝑉 for the LDA calculation and 4.3155𝑒𝑉 for the GGA (PBE) calculation, an absorption spectrum over an energy range from zero to 40𝑒𝑉. Here it is possible to observe an absorption region with a peak varying between 11.3 𝑒𝑉 (80 nm) and 15.2 𝑒𝑉 (110 nm). The entire spectrum is equivalent to an absorption band at the threshold of the blue to the ultraviolet region. Contextualizing this result, we emphasize that in the field of simulating organic crystals, some of them can behave as semiconductors or insulators.