对乙基苯酚是构成酪氨酸分子的重要基团,根据其光谱特性可以洞察酪氨酸的光学特性。我们采用超声分子束技术获得了对乙基苯酚的单色共振双光子电离光谱,首次报道了800~1 500cm-1范围的高分辨率激发态振动谱。配合量子化学理论计算分析了各谱对应的振动模式。结果表明取代基越长,分子的激发能越低;取代基的方向对激发能有明显影响;取代基会使苯环平面内的振动能量降低,但取代链的长短对振动能量没有明确影响。研究结果为分子的里德堡态、动力学和零动能光谱的相关研究提供了重要的参考数据。 P-ethyl phenol is an important group forming tyrosine molecules, according to its spectral properties can be insight into the optical properties of tyrosine. We acquired the monochromatic resonance two-photon ionization spectrum of p-ethylphenol using ultrasonic molecular beam technique, and the high-resolution excited-state vibrational spectrum in the range of 800 ~ 1500cm-1 was reported for the first time. According to quantum chemistry theory, the vibration modes of each spectrum are calculated and analyzed. The results show that the longer the substituent, the lower the excitation energy of the molecule; the direction of the substituent has a significant effect on the excitation energy; the substituent reduces the vibrational energy in the plane of the benzene ring, but the substitution of the chain length has no clear influence on the vibrational energy. The results provide important reference data for the study of Rydberg states, kinetics and zero kinetic energy spectra of the molecules.