scholarly journals Photo-assisted intersystem crossing: The predominant triplet formation mechanism in some isolated polycyclic aromatic molecules excited with pulsed lasers

2015 ◽  
Vol 143 (4) ◽  
pp. 044305 ◽  
Author(s):  
Philip M. Johnson ◽  
Trevor J. Sears
Keyword(s):  
Formation Mechanism ◽  
Intersystem Crossing ◽  
Pulsed Lasers ◽  
Aromatic Molecules ◽  
Polycyclic Aromatic ◽  
Triplet Formation

Photophysics of polycyclic aromatic molecules on semiconductor powders

1983 ◽  
Vol 105 (21) ◽  
pp. 6383-6389 ◽  
Author(s):  
K. Chandrasekaran ◽  
J. K. Thomas
Keyword(s):  
Aromatic Molecules ◽  
Polycyclic Aromatic

Triplet state dynamics in polycyclic aromatic molecules

1974 ◽  
Vol 27 (4) ◽  
pp. 556-561 ◽  
Author(s):  
Richard H. Clarke ◽  
John M. Hayes
Keyword(s):  
Triplet State ◽  
Aromatic Molecules ◽  
Polycyclic Aromatic

Graphene in Titan

2021 ◽  
Author(s):  
Rahul Kumar Kushwaha ◽  
Ambresh Mallya ◽  
Dipen Sahu ◽  
Jaya Krishna Meka ◽  
Sheng-Lung Chou ◽  
...  
Keyword(s):  
Room Temperature ◽  
Laboratory Experiments ◽  
Vacuum Ultraviolet ◽  
Physical Nature ◽  
Potassium Bromide ◽  
Aromatic Molecules ◽  
Transmission Electron ◽  
Polycyclic Aromatic ◽  
Plasma Spectrometer ◽  
Electron Microscopes

<p>Benzene (C<sub>6</sub>H<sub>6</sub>) ice has been observed in the Titan’s stratosphere [1], and benzonitrile (C<sub>6</sub>H<sub>5</sub>CN) is a possible constituent in the benzene and nitrogen-rich environment of Titan’s atmosphere [2]. The energetic processing of such aromatic molecules can synthesize large and complex aromatic molecules such as the Polycyclic Aromatic Hydrocarbons (PAHs). To-date a number of laboratory experiments have reported the formation of complex organics from the energetic processing of aromatic molecules [3-6]. In particular, Scanning Electron Microscopy (SEM) micrographs of the residues resulting from irradiated benzene ices are found to contain geometrically shaped particles [6]. Therefore, by employing electron microscopes, we can understand the physical nature of the dust leftover from the aromatic molecule irradiation.</p> <p>In the present investigation, we subjected benzonitrile ice made at 4 K to vacuum ultraviolet (9 eV) radiation at two beamlines, BL03 and BL21A2 of Taiwan Light Source at NSRRC, Taiwan. After irradiation, the ice was warmed to room temperature, which left a brownish residue on the Potassium Bromide (KBr) substrate. The VUV spectrum of the residue is observed to have characteristic aromatic signatures. The residue is then transferred to a quantifoil grid for High-Resolution Transmission Electron Microscope (HR- TEM) imaging. HR-TEM micrographs revealed the presence of graphene in the residue. This result suggests that N-graphene could be present in benzene and nitrogen-rich icy clouds of Titan. The high masses observed by the Cassini plasma spectrometer in Titan’s atmosphere could then be attributed to the presence of N-graphene along with the more common tholins [7].</p> <p><strong>References</strong></p> <p>[1] Vinatier S. et al. (2018) <em>Icarus, 310,</em> 89.</p> <p>[2] Loison J. C. et al. (2019) <em>Icarus 329,</em> 55.</p> <p>[3] Strazzulla G. et al. (1991) <em>A&A, 241</em>, 310.</p> <p>[4] Callahan M. P. et al. (2013) <em>Icarus, 226</em>, 1201.</p> <p>[5] James R. et al. (2019) <em>RSC Adv. 9</em> (10), 5453.</p> <p>[6] Rahul K. K. et al. (2020) <em>Spectrochim. Acta A, 231, </em>117797.</p> <p>[7] Rahul K. K. et al. (2020) <em>arXiv:2008.10011</em>.</p>

Two‐Photon Laser Excitation of Polycyclic Aromatic Molecules

1967 ◽  
Vol 47 (5) ◽  
pp. 1609-1619 ◽  
Author(s):  
Mark W. Dowley ◽  
Kenneth B. Eisenthal ◽  
Warner L. Peticolas
Keyword(s):  
Laser Excitation ◽  
Aromatic Molecules ◽  
Two Photon ◽  
Polycyclic Aromatic

Supramolecular Organization of Model Polycyclic Aromatic Molecules: Comparison of 2D and 3D Assemblies

ChemNanoMat ◽  
2019 ◽  
Vol 6 (1) ◽  
pp. 68-72
Author(s):  
Gijo Raj ◽  
Yoshihiro Kikkawa ◽  
Luca Catalano ◽  
Renu Pasricha ◽  
Yasuo Norikane ◽  
...  
Keyword(s):  
Supramolecular Organization ◽  
Aromatic Molecules ◽  
Polycyclic Aromatic ◽  
2D And 3D

scholarly journals Simultaneous multi-photon ionization of aromatic molecules in polymer solids with ultrashort pulsed lasers

2009 ◽  
Vol 475 (4-6) ◽  
pp. 240-244 ◽  
Author(s):  
Jiamo Guo ◽  
Tadahiro Togami ◽  
Hiroaki Benten ◽  
Hideo Ohkita ◽  
Shinzaburo Ito
Keyword(s):  
Pulsed Lasers ◽  
Aromatic Molecules ◽  
Photon Ionization ◽  
Ultrashort Pulsed Lasers

Effect of fatty acid on the formation of polycyclic aromatic hydrocarbons (PAHs) and the proposed formation mechanism during electric roasting

2019 ◽  
Vol 121 (12) ◽  
pp. 3193-3207
Author(s):  
Congcong Liu ◽  
Chong Wang ◽  
Keping Ye ◽  
Yun Bai ◽  
Xiaobo Yu ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Fatty Acid ◽  
Carbon Atom ◽  
Formation Mechanism ◽  
Aromatic Hydrocarbons ◽  
Meat Products ◽  
Content Type ◽  
Animal Fats ◽  
Animal Fat ◽  
Polycyclic Aromatic

Purpose The purpose of this paper is to elucidate the influences of the animal fat and fatty acid type on the formation of polycyclic aromatic hydrocarbons (PAHs) and to propose a formation mechanism of PAHs in fat during electric roasting, which is a method of non-direct-contact-flame heating. Design/methodology/approach The effects of animal fats and model fat on the formation of PAHs were valued on the basis of the ultra high-performance liquid chromatography data. The corresponding products of the FAME pyrolysis were detected by TG-FTIR. The proposal formation mechanism of PAHs was based on the summary of the literature. Findings Contrary to the International Agency for Research on Cancer, DF had higher risk with 280.53 ng/g of concentration after being roasted than the others animal fats of red meat in terms of PAHs formation. This research also ensured the importance of fat on PAHs formation, the concentration of PAHs in pure fats was higher after being electric roasted than that in meat patties and juice which made from corresponding animal fat. What is more, during pure animal fats and meat products being processed, less PAHs formed in the fat with lower extent of unsaturation and lower content of linolenate. In the same way, methyl linolenate demonstrated the significant increasement to PAHs formation compared to the other fatty acids. And, the number of carbon atom and the extent of unsaturation in fatty acid affects the formation of PAHs during roasting. The detection of alkene and alkane allows to propose a formation mechanism of PAHs during model fat being heated. Further study is required to elucidate the confirm moleculars during the formation of PAHs. Originality/value This work studied the effect of the carbon atom number and the unsaturation extent of fats and model fats on the formation of PAHs. This work also assure the important of alkene and alkane on the pyrolysis of model fats. This study also researched the formation and distribution of PAHs in pure fats and meat products after being heated.

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