Dynamics and quantitative analysis of aromatic compounds in the terahertz region
Abstract
The optical properties and characteristic spectral features of benzene, naphthalene, azobenzene, azobenzene-benzene mixtures and naphthalene-benzene mixture are investigated in the terahertz region using terahertz time-domain spectroscopy. To further resolve the origins of characteristic spectral features of aromatic compounds in terahertz region, the vibrational properties of benzene, naphthalene and azobenzene are studied using Gaussian 03 software package. The absorption of benzene, naphthalene originate from the induced dipole moment by molecular collision, crystal lattice vibration and interaction between molecular layers, respectively. The bending vibration of azobenzene is the major factor of absorption in terahertz region. Moreover, the quantitative analysis of azobenzene-benzene mixtures and naphthalene-benzene mixtures are studied. The refractive index of mixtures is found to vary linearly with concentration. The results can be used for the component and concentraion prediction of mixtures on the basis of Lambert-Beer law.
