Anthraquinone and its hydroxyl derivatives have been studied at the B3LYP/6-31G* level of density functional theory (DFT). The calculation results indicate that the title compounds have planar structures and exhibit strong intramolecular hydrogen bond, which has visible influence on the configuration and properties of the compounds. Normal-mode analyses have been performed to characterize the stable point and to determine the harmonic vibrational frequencies, and quite good results were achieved by comparing with the experimental data. The electronic spectra have been calculated too using the time-dependent DFT approach. The calculated results show that the first singlet exited state of the title compounds were obtained from the π→π* electron transition from the highest occupied molecular orbital to the lowest unoccupied molecular orbital. The standard thermodynamic properties of anthraquinones were calculated by the statistical thermodynamic method.

Key words: anthraquinone, density functional theory, IR spectrum, UV spectrum, thermodynamic property