Terahertz Time-Domain Spectroscopy of Dimethoate
This paper reported the theoretical and experimental vibrational frequencies of dimethoate,a kind of organophosphorus pesticides,in the frequency range from 0.2 to 2.5 THz(terahertz) respectively.The vibrational frequencies of dimethoate in the THz range were simulated by Becke3-Lee-Yang-Parr(B3LYP) algorithm of density functional theory.Simultaneously,we got the absorption and refraction spectra of dimethoate using THz time-domain spectroscopy(THz-TDS).It was found that dimethoate showed some distinct fingerprint spectra in the THz regeion and the theoretical results were in good agreement with the experimental results.Assisted by results from density functional calculations we interpret the origin of the observed vibrational frequencies as the intra-molecular and inter-molecular vibrations with the aid of Gaussian View 3.07.The results prove the feasibility of applying THz-TDS technique into the identification of dimethoate.