Determination of absolute photoionization cross-sections of oxygenated hydrocarbons

Xie, Ming; Zhou, Zhongyue; Wang, Zhandong; Chen, Dongna; Qi, Fei

doi:10.1016/j.ijms.2010.03.007

Cited by 57 publications

(53 citation statements)

References 33 publications

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“…To begin exploring this idea again, we have compared the calculated polarizability volume data for 27 molecular systems reported by Vallance and co-workers with experimental photoionization cross-section information obtained from a number of sources. [54][55][56][57][58][59][60][61][62] The outcome of this (for a photon energy of 11.5 eV) is presented in Fig. 10.…”

Section: B τ 1 Decay Associated Spectramentioning

confidence: 99%

Ultraviolet relaxation dynamics of aniline, N, N-dimethylaniline and 3,5-dimethylaniline at 250 nm

Thompson

Saalbach

Crane

et al. 2015

The Journal of Chemical Physics

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Time-resolved photoelectron imaging was used to investigate the electronic relaxation dynamics of gas-phase aniline, N, N-dimethylaniline, and 3,5-dimethylaniline following ultraviolet excitation at 250 nm. Our analysis was supported by ab initio coupled-cluster calculations evaluating excited state energies and (in aniline) the evolution of a range of excited state physical properties as a function of N-H bond extension. Due to a lack of consistency between several earlier studies undertaken in aniline, the specific aim of this present work was to gain new insight into the previously proposed non-adiabatic coupling interaction between the two lowest lying singlet excited states S1(ππ(∗)) and S2(3s/πσ(∗)). The methyl-substituted systems N, N-dimethylaniline and 3,5-dimethylaniline were included in order to obtain more detailed dynamical information about the key internal molecular coordinates that drive the S1(ππ(∗))/S2(3s/πσ(∗)) coupling mechanism. Our findings suggest that in all three systems, both electronic states are directly populated during the initial excitation, with the S2(3s/πσ(∗)) state then potentially decaying via either direct dissociation along the N-X stretching coordinate (X = H or CH3) or internal conversion to the S1(ππ(∗)) state. In aniline and N, N-dimethylaniline, both pathways most likely compete in the depletion of S2(3s/πσ(∗)) state population. However, in 3,5-dimethylaniline, only the direct dissociation mechanism appears to be active. This is rationalized in terms of changes in the relative rates of the two decay pathways upon methylation of the aromatic ring system.

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Section: B τ 1 Decay Associated Spectramentioning

confidence: 99%

Ultraviolet relaxation dynamics of aniline, N, N-dimethylaniline and 3,5-dimethylaniline at 250 nm

Thompson

Saalbach

Crane

et al. 2015

The Journal of Chemical Physics

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“…SPI mass spectra of seven involved aldehydes except formaldehyde (IE= 10.88 eV), as its IE is higher than the photon energy and it cannot be ionized by SPI, are shown in Figure 2. The fragment ions observed in the SPI mass spectra of the investigated aldehydes were attributed to neutral dissociation process that was discussed in depth by Hatano, Zimmerman, and coworkers [37][38][39] and displayed in Supporting Information Figure S1. Figure 2 demonstrates that neutral dissociation of the aldehyde molecules is the dominant SPI ionization channel for all aldehydes as they exhibit distinct fragment ions.…”

Section: Spi Mass Spectra Of Aldehydesmentioning

confidence: 87%

Rapid Identification and Quantification of Linear Olefin Isomers by Online Ozonolysis-Single Photon Ionization Time-of-Flight Mass Spectrometry

Xie

Chen

Lee

et al. 2015

J. Am. Soc. Mass Spectrom.

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Abstract. The specific locations of the double bonds in linear olefins can facilitate olefin catalytic synthetic reactions to improve the quality of target olefin products. We developed a simple and efficient approach based on single photon ionization time-offlight mass spectrometry (SPI-TOFMS) combined with online ozonolysis to identify and quantify the linear olefin double bond positional isomers. The online ozonolysis cleaved the olefins at the double bond positions that led to formation of corresponding characteristic aldehydes. The aldehydes were then detected by SPI-TOFMS to achieve unique spectrometric Bfingerprints^for each linear olefin to successfully identify the isomeric ones. To accurately quantify the isomeric components in olefin mixtures, an algorithm was proposed to quantify three isomeric olefin mixtures based on characteristic ion intensities and their equivalent ionization coefficients. The relative concentration errors for the olefin components were lower than 2.5% while the total analysis time was less than 2 min. These results demonstrate that the online ozonolysis SPI-TOFMS has the potential for real-time monitoring of catalytic olefin synthetic reactions.

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“…One important reason is that PI cross sections for a large and growing number of species are available for 118 nm PI [44][45][46][47][48][49][50][51][52][53]. By using the available cross section data, relative and even absolute number densities for detected species can be established-if one can assign a product at a given mass to a definite species.…”

Section: Effects Of Oxygen Co-addition On Post Discharge Products Formentioning

confidence: 99%

Post Discharge Chemistry of Aromatic Molecules in Rare Gas

Sulkes

2011

Plasma Chem Plasma Process

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We have employed 800 nm 150 fs laser pulses to carry out photoionization (PI) time-of-flight mass spectrometric detection of intermediates following corona discharges on aromatic molecules (alkylbenzenes and pyridine) in He, stabilized by subsequent supersonic gas expansions. Observed product peaks appear to be at least roughly in proportion to actual number densities; PI induced fragmentation of parent ions appears not to be excessive. Consequently, 800 nm fs PI should be useful for general product analysis applications in plasma chemistry. For most alkylbenzenes subjected to corona discharges in rare gas, the overall trends in product chemistry are similar in many respects to observed flame and pyrolysis chemistry in rare gases for the same species. Following discharge, as in those other cases, H deficient carbon radical fragments initially produced react in turn to form larger aromatic species. However, compared with flame/pyrolysis, discharge produced a larger number of fragment species, which can lead to a wider and somewhat different range of higher mass aromatic products. Co-addition of even a small component of O 2 to the discharge mixes has a potent effect in inhibiting formation of higher mass aromatic products in alkylbenzenes.

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Determination of absolute photoionization cross-sections of oxygenated hydrocarbons

Cited by 57 publications

References 33 publications

Ultraviolet relaxation dynamics of aniline, N, N-dimethylaniline and 3,5-dimethylaniline at 250 nm

Ultraviolet relaxation dynamics of aniline, N, N-dimethylaniline and 3,5-dimethylaniline at 250 nm

Rapid Identification and Quantification of Linear Olefin Isomers by Online Ozonolysis-Single Photon Ionization Time-of-Flight Mass Spectrometry

Post Discharge Chemistry of Aromatic Molecules in Rare Gas

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