【摘要】 利用真空紫外同步辐射和反射式飞行时间质谱研究了乙苯分子的光电离,通过测量母体分子的光电离质谱(PIMS)以及母体离子和主要碎片离子的光电离效率曲线(PIEs),确定了乙苯分子的电离能IE(C8H1+0)=(8.66±0.02)eV,主要碎片离子C7H7+和C6H6+的出现能分别为(10.81±0.02)和(10.99±0.02)eV;利用经验公式计算出产生碎片离子C7H7+和C6H6+需要的解离能(Ed)分别为(2.15±0.04)和(2.33±0.04)eV.结合相关的热化学参数,推算出C8H1+0,C7H7+和C6H6+的标准生成焓分别为865.5,927.2和1037.9kJ/mol.为进一步研究乙苯的大气光氧化反应机理提供了参考.更多还原

【Abstract】 The photoionization of ethylbenzene(C8H10) was investigated using the supersonic molecular beam,the reflectron-time-of-flight mass spectrometer(RTOF-MS) and vacuum ultraviolet(VUV) synchrotron radiation.The photoionization mass spectrum(PIMS) and the photoionzation efficiency(PIE) curves of the parent ion and some fragment ions were obtained.The ionization energy(IE) of C8H10 and the appearance energies(AEs) of C7H7+ and C6H6+ were measured to be(8.66 ± 0.02),(10.81 ± 0.02) and(10.99 ± 0.02) eV,respectively.The dissociation energies(Eds) to produce C7H7+ and C6H6+ were deduced to be(2.15 ± 0.04) and(2.33 ± 0.04) eV.The formation enthalpies of C8H 1+0,C7H7+ and C6H6+ were also deduced to be 865.5,927.2 and 1037.9 kJ/mol.All the parameters are very important for investigating the oxidation mechanism of ethylbenzene in the atmosphere.更多还原