Pan Yang, Zhang Lidong, Zhang Taichang, Guo Huijun, Hong Xin, Qi Fei
National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, PR China.
J Mass Spectrom. 2008 Dec;43(12):1701-10. doi: 10.1002/jms.1465.
Photoionization and dissociative photoionization characters of six quinones, including 1,2-naphthoquinone (1,2-NQ), 1,4-naphthoquinone (1,4-NQ), 9,10-phenanthroquinone (PQ), 9,10-anthraquinone (AQ), benz[a]- anthracene-7,12-dione (BAD) and 1,2-acenaphthylenedione (AND) have been studied with an infrared laser desorption/tunable synchrotron vacuum ultraviolet (VUV) photoionization mass spectrometry (IR LD/VUV PIMS) technique. Mass spectra of these compounds are obtained at different VUV photon energies. Consecutive losses of two carbon monoxide (CO) groups are found to be the main fragmentation pathways for all the quinones. Detailed dissociation processes are discussed with the help of ab initio B3LYP calculations. Ionization energies (IEs) of these quinones and appearance energies (AEs) of major fragments are obtained by measuring the photoionization efficiency (PIE) spectra. The experimental results are in good agreement with the theoretical data.
利用红外激光解吸/可调谐同步辐射真空紫外（VUV）光电离质谱（IR LD/VUV PIMS）技术研究了六种醌类化合物的光电离和解离光电离特性，这六种醌类化合物包括1,2-萘醌（1,2-NQ）、1,4-萘醌（1,4-NQ）、9,10-菲醌（PQ）、9,10-蒽醌（AQ）、苯并[a]蒽-7,12-二酮（BAD）和1,2-苊二酮（AND）。在不同的VUV光子能量下获得了这些化合物的质谱。发现连续失去两个一氧化碳（CO）基团是所有醌类化合物的主要碎裂途径。借助于从头算B3LYP计算讨论了详细的解离过程。通过测量光电离效率（PIE）光谱获得了这些醌类化合物的电离能（IEs）和主要碎片的出现能（AEs）。实验结果与理论数据吻合良好。
