Fluorine derivatives of piceatannol for photobiological and photophysical applications by DFT approach

Abstract

In the present work, we have calculated the electrical and optical properties of pure piceatannol (PI) and its six fluorinated derivatives (F1-F6). The first-principles calculations are performed in the framework of density functional theory employing the full-potential linearized augmented plane wave (FP-LAPW) method using PBE-GGA. It is found that the PI and its F-substituted derivatives are semiconductors with a HOMO-LUMO bandgap of 0.38 to 2.29 eV. Calculated partial density of states (DOS) of carbon and oxygen atoms show that the nature of C-O bonds is polar at PI. The effect of F substitution on the bandgap of PI are analyzed by comparing the DOS spectra. The size of the band gap can be controlled by changing the F sites in the PI. It is found that the band gap value decreases by substation of F at the F1, F2, F3, and F4 sites along with the F-O bonds at the LUMO state. However, in F5 and F6 sites, the change of the band gap is not significant. The dielectric behavior of the PI is observed at the y-direction. The calculated dielectric function spectra show the optical anisotropy at the x and the y-directions. The optical spectra revealed that F substitution in PI led to reduction of the optical band gap values and a red-shift occurs in the absorption spectra. The calculated absorption spectra of PI are in good agreement with the experimental data.