溴苯分子和间二溴苯分子的多光子解离电离质谱研究
|
摘要
溴苯类化合物在生产生活中被广泛应用，因而大量存在于土壤和水中。作为环境荷尔蒙类物质，此类化合物对人体健康有害，在其上升到对流层后，被紫外光光解会产生卤素原子，触发一系列化学反应，破坏臭氧分子，导致臭氧层的消耗，研究其多光子电离-解离过程可以更好的控制化学反应，所以研究溴苯类化合物的光解对环境保护有着重要意义。
本论文中，作者通过激光、分子束和飞行时间质谱对溴苯与1，3-二溴苯的多光子解离电离作了系统的研究。
(1)利用多光子电离与飞行时间质谱技术，在266nm和355nm激光作用下探测得到了溴苯分子解离电离质谱图。经分析认为355nm激光作用下，没有发生明显的解离电离。在266nm激光作用下，获得了溴苯分子的MPIF-TOF质谱。实验测得了各碎片离子占总离子信号的百分比对激光强度的依赖关系，并用这些实验结果对溴苯分子的多光子电离解离机理做了分析，还对C_6H_5~+，C_5H_3~+，C_4H_2~+，C_3H~+等碎片离子的可能形成过程作了讨论，结果证明母体分子吸收光子解离是主要通道，且碎片离子主要是经过离子离解阶梯模式产生的。
(2)在相同的实验条件下，研究了1，3-二溴苯分子的多光子解离电离过程。在266nm激光作用下其过程也主要是母体分子解离—中性碎片电离的过程，通过分析其分子的MPIF-TOF质谱，及观测各碎片离子占总离子信号的百分比对激光强度的依赖关系，得出产生的C_6H_4~+，C_5H_3~+，C_4H_2~+，C_3H~+等碎片离子主要是经过离子离解阶梯模式产生的，并推断出1，3-二溴苯母体分子和碎片离子可能的解离通道。
The compound of bromobenzene is widely applied in the production life. Thus, it exists in the soil and water in large quantity. Being the environment hormone class material, this kind of compound is harmful to the health of human body. Once it rises to the convection layer, the material will yield halogen atom by the ultraviolet ray photolysis. This will trigger a series of chemical reaction, and the ozone molecule is destroyed. And the course will cause the consumption of the ozone layer. Multiphoton ionization-dissociation process is studied in order that chemical reaction can be controlled better. So the study of photolysis of the monobromo-benzene class compound is significant to the protection of environment.
In this thesis, the Multiphoton ionization-dissociation process of bromobenzene and 1,3-dibromobenzene is researched in detail through the mass spectra of the laser, molecular beam and flight time.
(1)With the technique of multiphoton ionization and flight time mass spectra, the ionization-dissociation mass spectrogram of bromobenzene molecular can be detected under the effect of laser whose wavelength is 266nm and 355nm.After analysis, we get the conclusion that there is no obvious ionization-dissociation with the effect of the laser of 355nm, while under the effect of the laser of 266nm, MPIF-TOF mass spectrogram of bromobenzene molecular can be got with the method of mass spectra of multiphoton ionization-flight time. The experiment measured the dependency relation between the laser intensity and the signal percent of fragment ions out of all ions. Then, we analyzed the mechanics of multiphoton ionization-dissociation with the experimental results. Furthermore, we discussed the possible establishment of fragment ions such as C_6H_5~+, C_5H_3~+, C_4H_2~+, C_3H~+ . The result shows that the absorption of photon dissociation is the main channel, and most of ion fragments are produced by ion-fragment dissociation staircase.
(2)In the same experiment condition the multi-photon dissociation-ionization process of 1, 3-dibromobenzene were researched. Under the effect of 266nm laser its process is also mainly parent molecule dissociation and ionization of neutral fragment. We analyzed MPIF-TOF mass spectrogram of 1,3-dibromobenzene molecular and observed the dependency relation between the laser intensity and the signal percent of fragment ions out of all ions. The result shows that fragment ions such as C_6H_5~+, C_5H_3~+, C_4H_2~+, C_3H_2~+, are mainly generated by ion-fragment dissociation staircase. We also deduced the possible dissociation channel of 1,3-dibromobenzene parent molecule.
本论文中，作者通过激光、分子束和飞行时间质谱对溴苯与1，3-二溴苯的多光子解离电离作了系统的研究。
(1)利用多光子电离与飞行时间质谱技术，在266nm和355nm激光作用下探测得到了溴苯分子解离电离质谱图。经分析认为355nm激光作用下，没有发生明显的解离电离。在266nm激光作用下，获得了溴苯分子的MPIF-TOF质谱。实验测得了各碎片离子占总离子信号的百分比对激光强度的依赖关系，并用这些实验结果对溴苯分子的多光子电离解离机理做了分析，还对C_6H_5~+，C_5H_3~+，C_4H_2~+，C_3H~+等碎片离子的可能形成过程作了讨论，结果证明母体分子吸收光子解离是主要通道，且碎片离子主要是经过离子离解阶梯模式产生的。
(2)在相同的实验条件下，研究了1，3-二溴苯分子的多光子解离电离过程。在266nm激光作用下其过程也主要是母体分子解离—中性碎片电离的过程，通过分析其分子的MPIF-TOF质谱，及观测各碎片离子占总离子信号的百分比对激光强度的依赖关系，得出产生的C_6H_4~+，C_5H_3~+，C_4H_2~+，C_3H~+等碎片离子主要是经过离子离解阶梯模式产生的，并推断出1，3-二溴苯母体分子和碎片离子可能的解离通道。
The compound of bromobenzene is widely applied in the production life. Thus, it exists in the soil and water in large quantity. Being the environment hormone class material, this kind of compound is harmful to the health of human body. Once it rises to the convection layer, the material will yield halogen atom by the ultraviolet ray photolysis. This will trigger a series of chemical reaction, and the ozone molecule is destroyed. And the course will cause the consumption of the ozone layer. Multiphoton ionization-dissociation process is studied in order that chemical reaction can be controlled better. So the study of photolysis of the monobromo-benzene class compound is significant to the protection of environment.
In this thesis, the Multiphoton ionization-dissociation process of bromobenzene and 1,3-dibromobenzene is researched in detail through the mass spectra of the laser, molecular beam and flight time.
(1)With the technique of multiphoton ionization and flight time mass spectra, the ionization-dissociation mass spectrogram of bromobenzene molecular can be detected under the effect of laser whose wavelength is 266nm and 355nm.After analysis, we get the conclusion that there is no obvious ionization-dissociation with the effect of the laser of 355nm, while under the effect of the laser of 266nm, MPIF-TOF mass spectrogram of bromobenzene molecular can be got with the method of mass spectra of multiphoton ionization-flight time. The experiment measured the dependency relation between the laser intensity and the signal percent of fragment ions out of all ions. Then, we analyzed the mechanics of multiphoton ionization-dissociation with the experimental results. Furthermore, we discussed the possible establishment of fragment ions such as C_6H_5~+, C_5H_3~+, C_4H_2~+, C_3H~+ . The result shows that the absorption of photon dissociation is the main channel, and most of ion fragments are produced by ion-fragment dissociation staircase.
(2)In the same experiment condition the multi-photon dissociation-ionization process of 1, 3-dibromobenzene were researched. Under the effect of 266nm laser its process is also mainly parent molecule dissociation and ionization of neutral fragment. We analyzed MPIF-TOF mass spectrogram of 1,3-dibromobenzene molecular and observed the dependency relation between the laser intensity and the signal percent of fragment ions out of all ions. The result shows that fragment ions such as C_6H_5~+, C_5H_3~+, C_4H_2~+, C_3H_2~+, are mainly generated by ion-fragment dissociation staircase. We also deduced the possible dissociation channel of 1,3-dibromobenzene parent molecule.
引文
[1] 丛浦珠，苏克曼．分析化学手册第九分册[M]．北京：化学工业出版社，2000，177-180．
[2] 蔡继业，周士康，李书涛．激光与化学动力学[M]．安徽：安徽教育出版社，1992．115-124．
[3] 张秀，张冰．用共振增强多光子电离方法研究几种含溴化合物的光解[J]．化学学报，2006，64(7)：599-604．
[4] Zhang H, Zhu R S, Wang G J, Han K L, He G Z.Photodissociation of bromobenzene at 266nm[J].J.Chem.Phys, 1999,110(6):2922-2927.
[5] Tang B F, Zhu R S, Zhang B. Photodissociation of bromobenzene at 267 and 234 nm: experimental and theoretical investigation of the photodissociation mechanism[J].Chem.Phys.L,2003,381:617-622.
[6] S. H. Lim, J. C. Choe, M. S. Kim. C6H5Br~+→C6H5~+ + Br Occurs via Orbiting Transition State[J].J.Phys.Chem, 1998,102:7375-7381.
[7] A. Freedman, Yang S C, M. Kawasaki, R. Bersohn. Photodissociation of aryl and aryl-alkyl halides at 193nm:Fragment translational energy distributions[J].J.Chem.Phys, 1980,72(2): 1028-1033.
[8] 张霞，孔祥和，樊新岩．激光偏振特性对丙酮和氧气多光子电离质谱信号的影响[J]．原子与分子物理学，2005，22(3)：568-572．
[9] 刘玉芳，施德恒，孙金锋．355nm激光作用下Si(CH_3)_4分子的MPI质谱研究[J]．中国激光，2002，29(3)：218-222．
[10] 施德恒，刘玉芳．飞行时间质谱法研究Si(CH_3)_4分子的多光子解离和电离过程[J]．激光杂志，2001，22(6)：42-44．
[11] Brent D. Koplitz, Jeffrey K. Mcvey, Wavelength-dependent fragmentationin the resonance-enhanced ionization of bromobenzene[J].J.Chem.Phys,1984, 81(6):4963-4968.
[12] 郭文跃，张树东，方黎，魏杰，章莲蒂，蔡继业．丙酮和丙醛分子的多光子电离碎片化机理[J]．量子电子学报，1998，15(5)：447-452．
[13] Henry M.Rosenstock, Roger Stockbaue and Albert C.Parr. Photoelectron-photoion coincidence study of the bromobenzene ion[J].J.Chem.Phys, 1980,73(2):773-777.
[14] T. G. Dietz, M.A.Dunean, M.G.Liverman, and R.E.Smalley. Resonance enhanced two-photon ionization studies in a supersonic molecular beam: Bromobenzene and iodobenzene[J].J.Chem.Phys, 1980,73(10):4816-4821.
[15] 张柏林，魏杰，章莲蒂，姜芸芸，夏柱红，张冰，蔡继业．在532nm激光作用下n-C_4H_9I的多光子离解过程质谱研究[J]．量子电子学报，1999，16(5)：428-432．
[16] M. Kadi, E. Ivarsson, J. Davidsson. The photodissociation dynamics of o-, m- and p-bromotoluene in the gas phase studied with femtosecond pump-probe spectroscopy[J].Chemical Physics Letters,2004,38(4):35-39.
[17] 丁蕾，马靖，赵婷婷，顾学军，郑海洋，方黎，张为俊，CHAHK，KLMDH．260-285nm波段苯胺的共振增强多光子电离研究[J]．大气与环境光学学报，2006，1(2)：125-129．
[18] Malin Kadi, Jan Davidsson. The. photodissociation dynamics of dibromobenzenes and tribromobenzene in the gas phase studied with femtosecond pump-probe spectroscopy[J].Chemical Physics Letters,2003, 37(8):172-177.
[19] 丁蕾，马靖，顾学军，郑海洋，方黎，赵婷婷，张为俊．264～280nm波段萘的共振增强多光子电离研究[J]．原子与分子物理学报，2006，23(2)：192-196．
[20] 张柏林，魏杰，章莲蒂，夏柱红，顾学军，张冰．423—475nm的激光作用下呋喃分子的多光子电离离解研究[J]．物理学报，2000，49(4)：679-682．
[21] Oh Kyu Yoon, Wan Goo Hwang, Joong Chul Choe and Myung Soo Kim. Internal Energy Content of n-Butylbenzene,Bromobenzene, Iodobenzene and AnilineMolecular Ions Generated by Two-photonlonization at 266nm A Photodissociation Study[J].Rapid Commun. Mass Spectrom,1999,13: 1515-1521.
[22] Yeu Young Youn, Chan Ho Kwon, Joong Chul Choe, and Myung Soo Kimb. Discovery of long-lived excited electronic states of chlorobenzene, bromobenzene, benzonitrile, and phenyl acetylene cations[J].Journal of chemical physics,2002,117(6):2538-2545.
[23] M. Rasmusson, R. Lindh, N. Lascoux, A.N. Tarnovsky, M. Kadi, O. Kuhn, V.Sundstrom,E. Akesson. Photodissociation of bromobenzene in solution[J].Chemical Physics Letters,2003,36(7):759-766.
[24] Ya-Jun Liu, Petter Persson, Hans O. Karlsson, and Sten Lunell, Malin Kadi, Daniel Karlsson, and Jan Davidsson. Photodissociation of bromobenzene, dibromobenzene, and 1,3,5-tribromobenzene[J].Journal of chemical physics ,2003,120(14): 6502-6509.
[25] Ryuji Itakura, Jun Watanabe, Akiyoshi Hishikawa, and Kaoru Yamanouchi. Ionization and fragmentation dynamics of benzene in intense laser fields by tandem mass spectroscopy[J].Journal of chemical,2001,114(13):5598-5606.
[26] J.L.Durant, D.M.Rider, S.L.Anders0n, F.D.Proch, and R.N.Zare. Unimolecular dissociation rates of the chlorobenzene cation prepared by multiphoton ionization[J].J.Chem.Phys, 1984,80(5): 1817-1825.
[27] M.Saber Ahmed and Robert C. Dunbar. Chopped-laser two-photon photodissociation measurement of collisional relaxation in benzene ion[J].Chem.Phys,1988,89(8):4829-4832.
[28] Kong Xianghe, Zheng Haiyang, Zhang Bing. Comparison Experimental Investigation of Detection of Aromatic Molecules Pollution by Resonance Enhanced Multiphoton Ionization[J].Chinese Journal of quantum electronics,2001,18(5):429-433.
[29] 毕刚，谷莹红，牛菲，冯子刚，罗明道，田世忠．卤代苯类化合物光解速率与结构参数关系的研究[J]．环境科学研究，1998，11(4)：6-8．
[30] 赵文武，方黎，郑海洋．气溶胶飞行时间激光质谱仪在机动车尾气检测中的应用[J]．量子电子学报，2005，22(5)：754-757．
[31] Brent D. Koplitz and Jeffrey K. Mcvey. Metastable Ion Fragment Power Dependence in the Two-Photon Ionization of Benzene-d_6[J].Phys. Chem, 1985,89(13):2761-2764.
[32] 王艳秋，袁丽威，王利，何国钟，张志刚，王清月．用超短脉冲激光研究1，3-二氯苯激发态动力学[J]．高等学校化学学报，2004，25(8)：1517-1520．
[33] 姚关心，汪小丽，杜传梅，李慧敏，张先，郑贤锋，季学韩，崔执凤．丙酮分子的共振增强多光子电离解离过程的实验研究[J]．物理学报，2006，55(5)：2210-2214．
[2] 蔡继业，周士康，李书涛．激光与化学动力学[M]．安徽：安徽教育出版社，1992．115-124．
[3] 张秀，张冰．用共振增强多光子电离方法研究几种含溴化合物的光解[J]．化学学报，2006，64(7)：599-604．
[4] Zhang H, Zhu R S, Wang G J, Han K L, He G Z.Photodissociation of bromobenzene at 266nm[J].J.Chem.Phys, 1999,110(6):2922-2927.
[5] Tang B F, Zhu R S, Zhang B. Photodissociation of bromobenzene at 267 and 234 nm: experimental and theoretical investigation of the photodissociation mechanism[J].Chem.Phys.L,2003,381:617-622.
[6] S. H. Lim, J. C. Choe, M. S. Kim. C6H5Br~+→C6H5~+ + Br Occurs via Orbiting Transition State[J].J.Phys.Chem, 1998,102:7375-7381.
[7] A. Freedman, Yang S C, M. Kawasaki, R. Bersohn. Photodissociation of aryl and aryl-alkyl halides at 193nm:Fragment translational energy distributions[J].J.Chem.Phys, 1980,72(2): 1028-1033.
[8] 张霞，孔祥和，樊新岩．激光偏振特性对丙酮和氧气多光子电离质谱信号的影响[J]．原子与分子物理学，2005，22(3)：568-572．
[9] 刘玉芳，施德恒，孙金锋．355nm激光作用下Si(CH_3)_4分子的MPI质谱研究[J]．中国激光，2002，29(3)：218-222．
[10] 施德恒，刘玉芳．飞行时间质谱法研究Si(CH_3)_4分子的多光子解离和电离过程[J]．激光杂志，2001，22(6)：42-44．
[11] Brent D. Koplitz, Jeffrey K. Mcvey, Wavelength-dependent fragmentationin the resonance-enhanced ionization of bromobenzene[J].J.Chem.Phys,1984, 81(6):4963-4968.
[12] 郭文跃，张树东，方黎，魏杰，章莲蒂，蔡继业．丙酮和丙醛分子的多光子电离碎片化机理[J]．量子电子学报，1998，15(5)：447-452．
[13] Henry M.Rosenstock, Roger Stockbaue and Albert C.Parr. Photoelectron-photoion coincidence study of the bromobenzene ion[J].J.Chem.Phys, 1980,73(2):773-777.
[14] T. G. Dietz, M.A.Dunean, M.G.Liverman, and R.E.Smalley. Resonance enhanced two-photon ionization studies in a supersonic molecular beam: Bromobenzene and iodobenzene[J].J.Chem.Phys, 1980,73(10):4816-4821.
[15] 张柏林，魏杰，章莲蒂，姜芸芸，夏柱红，张冰，蔡继业．在532nm激光作用下n-C_4H_9I的多光子离解过程质谱研究[J]．量子电子学报，1999，16(5)：428-432．
[16] M. Kadi, E. Ivarsson, J. Davidsson. The photodissociation dynamics of o-, m- and p-bromotoluene in the gas phase studied with femtosecond pump-probe spectroscopy[J].Chemical Physics Letters,2004,38(4):35-39.
[17] 丁蕾，马靖，赵婷婷，顾学军，郑海洋，方黎，张为俊，CHAHK，KLMDH．260-285nm波段苯胺的共振增强多光子电离研究[J]．大气与环境光学学报，2006，1(2)：125-129．
[18] Malin Kadi, Jan Davidsson. The. photodissociation dynamics of dibromobenzenes and tribromobenzene in the gas phase studied with femtosecond pump-probe spectroscopy[J].Chemical Physics Letters,2003, 37(8):172-177.
[19] 丁蕾，马靖，顾学军，郑海洋，方黎，赵婷婷，张为俊．264～280nm波段萘的共振增强多光子电离研究[J]．原子与分子物理学报，2006，23(2)：192-196．
[20] 张柏林，魏杰，章莲蒂，夏柱红，顾学军，张冰．423—475nm的激光作用下呋喃分子的多光子电离离解研究[J]．物理学报，2000，49(4)：679-682．
[21] Oh Kyu Yoon, Wan Goo Hwang, Joong Chul Choe and Myung Soo Kim. Internal Energy Content of n-Butylbenzene,Bromobenzene, Iodobenzene and AnilineMolecular Ions Generated by Two-photonlonization at 266nm A Photodissociation Study[J].Rapid Commun. Mass Spectrom,1999,13: 1515-1521.
[22] Yeu Young Youn, Chan Ho Kwon, Joong Chul Choe, and Myung Soo Kimb. Discovery of long-lived excited electronic states of chlorobenzene, bromobenzene, benzonitrile, and phenyl acetylene cations[J].Journal of chemical physics,2002,117(6):2538-2545.
[23] M. Rasmusson, R. Lindh, N. Lascoux, A.N. Tarnovsky, M. Kadi, O. Kuhn, V.Sundstrom,E. Akesson. Photodissociation of bromobenzene in solution[J].Chemical Physics Letters,2003,36(7):759-766.
[24] Ya-Jun Liu, Petter Persson, Hans O. Karlsson, and Sten Lunell, Malin Kadi, Daniel Karlsson, and Jan Davidsson. Photodissociation of bromobenzene, dibromobenzene, and 1,3,5-tribromobenzene[J].Journal of chemical physics ,2003,120(14): 6502-6509.
[25] Ryuji Itakura, Jun Watanabe, Akiyoshi Hishikawa, and Kaoru Yamanouchi. Ionization and fragmentation dynamics of benzene in intense laser fields by tandem mass spectroscopy[J].Journal of chemical,2001,114(13):5598-5606.
[26] J.L.Durant, D.M.Rider, S.L.Anders0n, F.D.Proch, and R.N.Zare. Unimolecular dissociation rates of the chlorobenzene cation prepared by multiphoton ionization[J].J.Chem.Phys, 1984,80(5): 1817-1825.
[27] M.Saber Ahmed and Robert C. Dunbar. Chopped-laser two-photon photodissociation measurement of collisional relaxation in benzene ion[J].Chem.Phys,1988,89(8):4829-4832.
[28] Kong Xianghe, Zheng Haiyang, Zhang Bing. Comparison Experimental Investigation of Detection of Aromatic Molecules Pollution by Resonance Enhanced Multiphoton Ionization[J].Chinese Journal of quantum electronics,2001,18(5):429-433.
[29] 毕刚，谷莹红，牛菲，冯子刚，罗明道，田世忠．卤代苯类化合物光解速率与结构参数关系的研究[J]．环境科学研究，1998，11(4)：6-8．
[30] 赵文武，方黎，郑海洋．气溶胶飞行时间激光质谱仪在机动车尾气检测中的应用[J]．量子电子学报，2005，22(5)：754-757．
[31] Brent D. Koplitz and Jeffrey K. Mcvey. Metastable Ion Fragment Power Dependence in the Two-Photon Ionization of Benzene-d_6[J].Phys. Chem, 1985,89(13):2761-2764.
[32] 王艳秋，袁丽威，王利，何国钟，张志刚，王清月．用超短脉冲激光研究1，3-二氯苯激发态动力学[J]．高等学校化学学报，2004，25(8)：1517-1520．
[33] 姚关心，汪小丽，杜传梅，李慧敏，张先，郑贤锋，季学韩，崔执凤．丙酮分子的共振增强多光子电离解离过程的实验研究[J]．物理学报，2006，55(5)：2210-2214．