丁酮3s里德堡态的超快光解动力学研究

罗金龙; 凌丰姿; 李帅; 王艳梅; 张冰

doi:10.7498/aps.66.023301

留言板

尊敬的读者、作者、审稿人, 关于本刊的投稿、审稿、编辑和出版的任何问题, 您可以本页添加留言。我们将尽快给您答复。谢谢您的支持!

姓名

邮箱

手机号码

标题

留言内容

验证码

摘要

本文采用195.8 nm飞秒激光将丁酮分子激发到S2（n，3s）里德堡态，在800 nm探测光的作用下获得时间分辨的飞行时间质谱.对实验结果的分析表明，由于丁酮位置具有一个甲基和一个乙基，使得Norrish I型解离反应表现出丰富的动力学特征.母体离子瞬态衰减的时间常数为（2.230.02）ps.丙酰基离子瞬态衰减与母体类似，只有一个为（2.150.02）ps的时间常数，说明丙酰基离子来自于母体的解离性电离.乙酰基离子的时间曲线拟合得到四个时间常数：1=（2.400.15）ps，2=（1.100.25）ps，3=（0.080.02）ps，4=（17.720.80）ps，分别对应于S2S1的内转换，S1态生成CH3CO（）的初步解离，CH3CO（）快速内转换为CH3CO（），以及CH3CO（）基态上的二次解离.丁酮分子-CC键的解离存在分子内振动能量再分配（IVR）与势垒解离两种竞争的解离通道，但在该实验条件下，我们认为是通过分子内振动能量再分配通道发生解离的结果.

关键词:

作者及机构信息

1.
昆明学院物理科学与技术系, 昆明 650214;

2.
中国科学院武汉物理与数学研究所, 波谱与原子分子物理国家重点实验室, 武汉 430071

通信作者: 张冰, bzhang@wipm.ac.cn

基金项目: 国家重点基础研究发展计划（批准号：2013CB922200）和国家自然科学基金（批准号：21573279，21273274）资助的课题.

参考文献

[1]	Vacher J R, Jorand F, Blin-Simiand N, Pasquiers S 2008 Int. J. Mass Spectrom. 273 117
[2]	Mu Y, Mellouki A 2000 J. Photochem. Photobiol. A 134 31
[3]	Haas Y 2004 Photochem. Photobiol. Sci. 3 6
[4]	Noyes W A, Porter G B, Jolley J E 1956 Chem. Rev. 56 49
[5]	Diau E W G, Kötting C, Zewail A H 2003 Chem. Phys. Lett. 380 411
[6]	Chen W K, Ho J W, Cheng P Y 2005 J. Phys. Chem. A 109 6805
[7]	Chen W K, Cheng P Y 2005 J. Phys. Chem. A 109 6818
[8]	Chen W K, Ho J W, Cheng P Y 2005 Chem. Phys. Lett. 415 291
[9]	O Toole L, Brint P, Kosmidis C, Boulakis G, Tsekeris P 1991 J. Chem. Soc., Faraday Trans. 87 3343
[10]	Loo R O, Hall G E, Houston P L 1989 J. Chem. Phys. 90 4222
[11]	Zou P, McGivern W S, North S W 2000 Phys. Chem. Chem. Phys. 2 3785
[12]	Wei Z, Zhang F, Wang Y, Zhang B 2007 Chin. J. Chem. Phys. 20 419
[13]	Zhang R R, Qin C C, Long J Y, Yang M H, Zhang B 2012 Acta Phys.-Chim. Sin. 28 522
[14]	Sun C K, Hu Z, Yang X, Jin M X, Hu W C, Ding D J 2011 Chem. Res. Chinese Universities 27 508
[15]	Shen L, Zhang B, Suits A G 2010 J. Phys. Chem. A 114 3114
[16]	Traeger J C 1985 Org. Mass Spectrom. 20 223
[17]	Traeger J C, McLouglin R G, Nicholson A J C 1982 J. Am. Chem. Soc. 104 5318
[18]	Owrutsky J C, Baronavski A P 1998 J. Chem. Phys. 108 6652
[19]	Mordaunt D H, Osborn D L, Neumark D M 1998 J. Chem. Phys. 108 2448
[20]	Shibata T, Li H Y, Katayanagi H, Suzuki T 1998 J. Phys. Chem. A 102 3643
[21]	Deshmukh S, Myers J D, Xantheas S S, Hess W P 1994 J. Phys. Chem. 98 12535
[22]	Kroger P M, Riley S J 1977 J. Chem. Phys. 67 4483

施引文献

[1]	Vacher J R, Jorand F, Blin-Simiand N, Pasquiers S 2008 Int. J. Mass Spectrom. 273 117
[2]	Mu Y, Mellouki A 2000 J. Photochem. Photobiol. A 134 31
[3]	Haas Y 2004 Photochem. Photobiol. Sci. 3 6
[4]	Noyes W A, Porter G B, Jolley J E 1956 Chem. Rev. 56 49
[5]	Diau E W G, Kötting C, Zewail A H 2003 Chem. Phys. Lett. 380 411
[6]	Chen W K, Ho J W, Cheng P Y 2005 J. Phys. Chem. A 109 6805
[7]	Chen W K, Cheng P Y 2005 J. Phys. Chem. A 109 6818
[8]	Chen W K, Ho J W, Cheng P Y 2005 Chem. Phys. Lett. 415 291
[9]	O Toole L, Brint P, Kosmidis C, Boulakis G, Tsekeris P 1991 J. Chem. Soc., Faraday Trans. 87 3343
[10]	Loo R O, Hall G E, Houston P L 1989 J. Chem. Phys. 90 4222
[11]	Zou P, McGivern W S, North S W 2000 Phys. Chem. Chem. Phys. 2 3785
[12]	Wei Z, Zhang F, Wang Y, Zhang B 2007 Chin. J. Chem. Phys. 20 419
[13]	Zhang R R, Qin C C, Long J Y, Yang M H, Zhang B 2012 Acta Phys.-Chim. Sin. 28 522
[14]	Sun C K, Hu Z, Yang X, Jin M X, Hu W C, Ding D J 2011 Chem. Res. Chinese Universities 27 508
[15]	Shen L, Zhang B, Suits A G 2010 J. Phys. Chem. A 114 3114
[16]	Traeger J C 1985 Org. Mass Spectrom. 20 223
[17]	Traeger J C, McLouglin R G, Nicholson A J C 1982 J. Am. Chem. Soc. 104 5318
[18]	Owrutsky J C, Baronavski A P 1998 J. Chem. Phys. 108 6652
[19]	Mordaunt D H, Osborn D L, Neumark D M 1998 J. Chem. Phys. 108 2448
[20]	Shibata T, Li H Y, Katayanagi H, Suzuki T 1998 J. Phys. Chem. A 102 3643
[21]	Deshmukh S, Myers J D, Xantheas S S, Hess W P 1994 J. Phys. Chem. 98 12535
[22]	Kroger P M, Riley S J 1977 J. Chem. Phys. 67 4483

引用本文:

Citation:

计量

文章访问数: 1541
PDF下载量: 265
被引次数: 0

丁酮3s里德堡态的超快光解动力学研究

1. 昆明学院物理科学与技术系, 昆明 650214;

2. 中国科学院武汉物理与数学研究所, 波谱与原子分子物理国家重点实验室, 武汉 430071

通信作者: 张冰, bzhang@wipm.ac.cn

基金项目:

国家重点基础研究发展计划（批准号：2013CB922200）和国家自然科学基金（批准号：21573279，21273274）资助的课题.

收稿日期: 2016-09-12

修回日期: 2016-11-01

刊出日期: 2017-01-20

摘要: 本文采用195.8 nm飞秒激光将丁酮分子激发到S2（n，3s）里德堡态，在800 nm探测光的作用下获得时间分辨的飞行时间质谱.对实验结果的分析表明，由于丁酮位置具有一个甲基和一个乙基，使得Norrish I型解离反应表现出丰富的动力学特征.母体离子瞬态衰减的时间常数为（2.230.02）ps.丙酰基离子瞬态衰减与母体类似，只有一个为（2.150.02）ps的时间常数，说明丙酰基离子来自于母体的解离性电离.乙酰基离子的时间曲线拟合得到四个时间常数：1=（2.400.15）ps，2=（1.100.25）ps，3=（0.080.02）ps，4=（17.720.80）ps，分别对应于S2S1的内转换，S1态生成CH3CO（）的初步解离，CH3CO（）快速内转换为CH3CO（），以及CH3CO（）基态上的二次解离.丁酮分子-CC键的解离存在分子内振动能量再分配（IVR）与势垒解离两种竞争的解离通道，但在该实验条件下，我们认为是通过分子内振动能量再分配通道发生解离的结果.

关键词:

Ultrafast photodissociation dynamics of butanone in 3s Rydberg state

1.
Department of Physical Science and Technology, Kunming University, Kunming 650214, China;

2.
State Key Laboratory of Spectroscopyand Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China

Fund Project:

Project supported by the National Basic Research Program of China (Grant No. 2013CB922200) and the National Natural Science Foundation of China (Grant Nos. 21573279, 21273274).

Received Date: 12 September 2016

Accepted Date: 01 November 2016

Published Online: 20 January 2017

Abstract: The initiation and subsequent control or exploration study of chemical transformation in real time by using ultrashort laser pulses aim at femtochemistry. The real-time investigations of ultrafast dynamics of excited molecules in gas and condensed phases have attracted a great deal of attention over the last two decades. As a kind of important organic compound, aliphatic ketone is an area of much interest for many research fields, especially for atmospheric photochemistry. Via photodissociation reaction, it can release carbonyl radical whose chemical character is active and can react with hydroxyl easily. As a typical aliphatic ketone, butanone has been a research focus over the past decades. The ultrafast dissociation dynamics of butanone after excitation to the second electronically excited state (S2) with a 195.8 nm pump pulse is studied by the femtosecond pump-probe technique combined with the time-of-flight mass spectrometry (TOF-MS). Time-resolved mass spectrometry (TRMS) has proven to be a powerful technique to study the ultrafast dynamics of excited states in molecules. In this technique, the MCP detector is capable of recording time-resolved ion yield measurements of different cations by monitoring the current output directly from the anode by using an oscilloscope. This enables a time-of-flight mass spectrum to be recorded at each delay time, which is controlled by a delay stage, and the measured total signal is then integrated, yielding a time-resolved ion yield transient, which is conducted by LABVIEW software. The pump wavelength in this work is set to be 195.8 nm and the probe laser wavelength is centered at 800 nm. The complex ultrafast dynamics in butanone with 3s Rydberg state excitation and its possible decay paths and following dissociation mechanism are given. Experimental results show that the Norrish I type dissociation kinetics of butanone exhibit rich features, for it has a methyl group and an ethyl group at position. The decay time constant of the parent transient is approximately 2.23 ps0.02 ps. There is only one time constant of 2.15 ps0.02 ps for the fitting of the propionyl transient. The best fit of acetyltransient is obtained with four time constants:1=(2.400.15) ps, 2=(1.100.25) ps, 3=(0.080.02) ps, and 4=(17.720.80) ps, corresponding to S2S1 internal conversion, the primary dissociation of the S1 state generating CH3CO(), internal conversion and secondary dissociation of CH3CO() respectively. Two competitive -CC bond dissociation processes are observed and discussed. They are dissociation channels through intramolecular vibrational energy redistribution (IVR) and/or by getting over the dissociation barrier in -cleavage of butanone. But hereunder the condition of this experiment, the dissociation is the result of IVR.

Keywords:

全文HTML

参考文献 (22)

搜索

留言板