The photoionization and photodissociative ionization processes of p-nitrotoluene(C,H,NO,) have been studied using the photoionization mass spectrometry wlth synchrotronradiation(SR) as the light source- The ionization...The photoionization and photodissociative ionization processes of p-nitrotoluene(C,H,NO,) have been studied using the photoionization mass spectrometry wlth synchrotronradiation(SR) as the light source- The ionization potential (PI) of p-nitrotoluene and eightappearance potentials(P.) of the ionic fragment from the SR photodissociative ionization ofC:H:NO, have been measured. Based on the mass spectra of C,H:NO, obtained with SR pho-tolonization and the relationship of energy in the processes, the most possible channels ofphotodissociative ionization of p-nltrotoluene have been analyzed.展开更多
Photoionization and Photodissociation of epichlorohydrin are performed using a time-of-flight mass spectrometer（TOF-MS） with vacuum ultraviolet（VUV） photons from Hefei synchrotron radiation source. Photoionization...Photoionization and Photodissociation of epichlorohydrin are performed using a time-of-flight mass spectrometer（TOF-MS） with vacuum ultraviolet（VUV） photons from Hefei synchrotron radiation source. Photoionization mass spectrum and photoionization efficiency（PIE） curves of the fragment ions are measured. The appearance potentials of the fragment ions are obtained from their PIE curves. From these data, the formation enthalpies of some ions have been evaluated and their possible channels of dissociative photoionization have been discussed. The experimental results show that the mother ion of epichlorohydrin is unstable and the chlorine atom is easily lost to form ring C3H5O+ ion. Other fragment ions come from the dissociation of C3H5O+ ions.展开更多
In this paper,the photoionization and photodissociative ionization processes of p aminoazobenzene (pAAB,C 12 H 11 N 3) using coincidence technology with vacuum ultraviolet synchrotron radiation (SR) photoionizaton mas...In this paper,the photoionization and photodissociative ionization processes of p aminoazobenzene (pAAB,C 12 H 11 N 3) using coincidence technology with vacuum ultraviolet synchrotron radiation (SR) photoionizaton mass spectroscopy are reported.The ionization potential (IP) of this molecule and the appearance potentials (AP) of the important ionic fragments from the SR photodissociative ionization of pAAB have been measured.On the basis of the IP(C 12 H 11 N 3) and AP measured in this experiment and the IP(C 6H 5) from the literature,the dissociative energy D 0(C 6H 5-N 2C 6H 4NH 2),D 0(C 6H + 5-N 2C 6H 4NH 2),D 0(C 6H 5-N 2C 6H 4NH + 2),D 0(C 6H 5N 2-C 6H 4NH + 2) and ionization potential of free radical N 2C 6H 4NH 2 have been evaluated.Based on the results of the mass spectroscopy of pAAB obtained with SR photoionization,the possible channels of photodissociative ionization of pAAB have been analyzed.The processes(molecular ions or the fregmental ions) giving rise to the ions C 6H + 5 and C 6H 6N + need further study.展开更多
为研究α-蒎稀的光电离解离机制,采用同步辐射光电离质谱,在7.9~15.5 e V能量范围内研究了α-蒎稀的紫外光电离解离,对α-蒎稀的电离解离能及其碎片离子的出现势进行了理论分析.实验测得光电离效率曲线,从光电离效率曲线中获得α-蒎稀C_...为研究α-蒎稀的光电离解离机制,采用同步辐射光电离质谱,在7.9~15.5 e V能量范围内研究了α-蒎稀的紫外光电离解离,对α-蒎稀的电离解离能及其碎片离子的出现势进行了理论分析.实验测得光电离效率曲线,从光电离效率曲线中获得α-蒎稀C_(10)H_(16)的电离能和碎片离子C_9H^+_(13),C_7H^+_(10),C_3H_6^+及CHH_3^+的出现势.用Gaussian 03理论方法计算了C_(10)H_(16)和主要的光解离碎片的总能量,用高级能量计算方法计算了C_(10)H_(16)的电离能和部分碎片离子的出现势及主要的解离通道的离解能.根据实验和理论计算结果,分析了产生碎片离子的主要的解离通道.分析表明实验测得的结果与理论计算提出的C_(10)H_(16)的光解离通道获得的解离能符合得较好.展开更多
文摘The photoionization and photodissociative ionization processes of p-nitrotoluene(C,H,NO,) have been studied using the photoionization mass spectrometry wlth synchrotronradiation(SR) as the light source- The ionization potential (PI) of p-nitrotoluene and eightappearance potentials(P.) of the ionic fragment from the SR photodissociative ionization ofC:H:NO, have been measured. Based on the mass spectra of C,H:NO, obtained with SR pho-tolonization and the relationship of energy in the processes, the most possible channels ofphotodissociative ionization of p-nltrotoluene have been analyzed.
文摘Photoionization and Photodissociation of epichlorohydrin are performed using a time-of-flight mass spectrometer（TOF-MS） with vacuum ultraviolet（VUV） photons from Hefei synchrotron radiation source. Photoionization mass spectrum and photoionization efficiency（PIE） curves of the fragment ions are measured. The appearance potentials of the fragment ions are obtained from their PIE curves. From these data, the formation enthalpies of some ions have been evaluated and their possible channels of dissociative photoionization have been discussed. The experimental results show that the mother ion of epichlorohydrin is unstable and the chlorine atom is easily lost to form ring C3H5O+ ion. Other fragment ions come from the dissociation of C3H5O+ ions.
文摘In this paper,the photoionization and photodissociative ionization processes of p aminoazobenzene (pAAB,C 12 H 11 N 3) using coincidence technology with vacuum ultraviolet synchrotron radiation (SR) photoionizaton mass spectroscopy are reported.The ionization potential (IP) of this molecule and the appearance potentials (AP) of the important ionic fragments from the SR photodissociative ionization of pAAB have been measured.On the basis of the IP(C 12 H 11 N 3) and AP measured in this experiment and the IP(C 6H 5) from the literature,the dissociative energy D 0(C 6H 5-N 2C 6H 4NH 2),D 0(C 6H + 5-N 2C 6H 4NH 2),D 0(C 6H 5-N 2C 6H 4NH + 2),D 0(C 6H 5N 2-C 6H 4NH + 2) and ionization potential of free radical N 2C 6H 4NH 2 have been evaluated.Based on the results of the mass spectroscopy of pAAB obtained with SR photoionization,the possible channels of photodissociative ionization of pAAB have been analyzed.The processes(molecular ions or the fregmental ions) giving rise to the ions C 6H + 5 and C 6H 6N + need further study.
基金The Scientific Research Foundation of the Education Ministry for Returned Chinese Scholars,China(No.[2013]693)the National Natural Science Foundation of China(No.11404039)
文摘为研究α-蒎稀的光电离解离机制,采用同步辐射光电离质谱,在7.9~15.5 e V能量范围内研究了α-蒎稀的紫外光电离解离,对α-蒎稀的电离解离能及其碎片离子的出现势进行了理论分析.实验测得光电离效率曲线,从光电离效率曲线中获得α-蒎稀C_(10)H_(16)的电离能和碎片离子C_9H^+_(13),C_7H^+_(10),C_3H_6^+及CHH_3^+的出现势.用Gaussian 03理论方法计算了C_(10)H_(16)和主要的光解离碎片的总能量,用高级能量计算方法计算了C_(10)H_(16)的电离能和部分碎片离子的出现势及主要的解离通道的离解能.根据实验和理论计算结果,分析了产生碎片离子的主要的解离通道.分析表明实验测得的结果与理论计算提出的C_(10)H_(16)的光解离通道获得的解离能符合得较好.
