1-萘酚的太赫兹光谱实验及理论研究

Experimental and theoretical study of terahertz spectroscopy of 1-naphthol

1-萘酚是煤化工产物萘的合成产物,对环境和人体健康有危害.采用太赫兹时域光谱(THz-TDS)技术,获得了1-萘酚在0.5~4.0 THz范围内的实测太赫兹吸收谱,同时运用密度泛函理论(DFT)平面波赝势模型对1-萘酚晶胞模型进行理论光谱计算,探讨了平面波截断能在800~1600 eV范围内对理论光谱的影响,并对吸收峰的振动模式进行了理论归属.实验结果表明,1-萘酚在0.5~4.0 THz范围内有1.14 THz、1.60 THz、2.16 THz、2.81 THz、3.56 THz共5个吸收峰,平面波截断能1400 eV下得到的理论吸收谱与实测吸收谱在吸收峰个数、峰位、归一化峰强度上均有较好的一致性,5个吸收峰的振动模式均是以两元环为平面的受氢键束缚的面外摇摆振动或者面内扭转振动引起的.这为太赫兹技术对1-萘酚的识别提供了实验和理论基础,具有一定的理论意义和实际应用价值.

1-naphthol is a synthetic product of the coal chemical product naphthalene,which is harmful to the environment and human health.The experimental terahertz absorption spectrum of 1-naphthol in the range of 0.5~4.0 THz was obtained by using terahertz time-domain spectroscopy(THz-TDS)technique.Meanwhile,the theoretical spectra of 1-naphthol cell model were calculated by using density functional theory(DFT)plane wave pseudopotential model.The influence of plane wave cutoff energy on the theoretical spectra in the range of 800~1600 eV was discussed,and the vibration modes of absorption peaks were theoretically assigned.The results showed that 1-naphthol has five absorption peaks in the range of 0.5~4.0 THz,including 1.14 THz,1.60 THz,2.16 THz,2.81 THz and 3.56 THz.The theoretical absorption spectrum obtained at 1400 eV and the measured absorption spectrum have good consistency in the number of absorption peaks,peak position and normalized peak intensity.The vibration modes of the five absorption peaks are caused by the out-of-plane oscillation vibration or in-plane torsional vibration bound by hydrogen bonds in the plane of the two-dimensional ring.This provides an experimental and theoretical basis for the identification of 1-naphthol by terahertz technology,which has certain theoretical significance and practical application value.