丁酮分子的多光子电离-离解机理

研究了丁酮分子经(n0,3d)共振的多光子电离-离解机理(MPID).多光子电离-飞行时间质谱测得的主要离子产物是C2H3O+和CH3CH+2,C2H3O+的强度为CH3CH+2的2～5倍,还有少量C2H+2,C2H+3和CH+3离子,未见到母体离子.主要离子产物的分质量多光了电离谱结构相似,而各离子产物的光强指数不同.实验结果说明丁酮分子的多光子电离-离解机理符合母体离子阶梯模型,文中用梯开关模型对主要产物离子的产生机理进行了解释.

Multiphoton ionization dissociation mechanism of 2-Butanone

Multiphoton ionization dissociation(MPID) mechanism has been studied on 2-butanone molecule resonated via ( n o,3d ) state by 3 photons. The main MPID products are C 2H 3O + and CH 3CH + 2, the intensity of C 2H 3O + is 1～4 times larger than that of CH 3CH + 2, and some mionr ions C 2H + 2, C 2H + 3 and CH + 3 are also observed in the whole experimentally spectral region, where as no parent ion is observed. The mass selected resonance enhanced multiphoton ionization dissociation spectra take a similar feature, but the laser power indexes of the fragmental ions are different from each other. Based on the experimental results, the multiphoton ionization dissociation mechanism is made out to accord with "molecular ion ladder model". The producing mechanism of the main ions has been discussed in detail according to "ladder switching".