Radical cation formation during the adsorption of polycyclic aromatic hydrocarbons on platinum oxide

1973 ◽  
Vol 26 (1) ◽  
pp. 221 ◽  
Author(s):  
JL Garnett ◽  
KJ Nicol ◽  
A Rainis
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Radical Cation ◽  
Aromatic Hydrocarbons ◽  
Hyperfine Splitting ◽  
Radical Cations ◽  
Platinum Oxide ◽  
Adsorbed Species ◽  
Experimental Conditions ◽  
Polycyclic Aromatic

Experimental conditions are reported for resolving the hyperfine splitting of e.p.r. spectra obtained from the interaction of polycyclic aromatic hydrocarbons with platinum oxide. By contrast with earlier interpretations where only a singlet was obtained even with perylene, the present results indicate that the adsorbed species are radical cations.

scholarly journals Effects of Neutralization, Decoloration, and Deodorization on Polycyclic Aromatic Hydrocarbons during Laboratory-Scale Oil Refining Process

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Yuxiang Ma ◽  
Longkai Shi ◽  
Yulan Liu ◽  
Qiyu Lu
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Refining Process ◽  
Laboratory Scale ◽  
Oil Refining ◽  
Security Risk ◽  
Experimental Conditions ◽  
Polycyclic Aromatic ◽  
Deodorized Oils

The influence of technological operations during oil refining process on polycyclic aromatic hydrocarbons (PAHs) in neutralized, bleached, and deodorized oils was investigated on the basis of laboratory-scale study. Under the best experimental conditions, benzo[a]pyrene decreased by 85.1%, 99.7%, and 40.8% in neutralized, bleached, and deodorized oils, respectively. Total of 16 analytes decreased by 55.7%, 87.5%, and 47.7%, respectively. Bleaching with activated charcoal was the most efficient procedure to reduce PAHs in crude oil. Neutralization had a modest influence on sixteen analytes; however, deodorization was only responsible for a slight decrease in the light PAHs and heavy PAHs contents. Data obtained in this study suggest that the use of activated carbon during oil refining process is highly recommended; moreover, these results provide a useful guidance for oil refining plant to reduce security risk and ensure the quality of the vegetable oil products.

ROTATIONAL SPECTRA OF A SERIES OF POLYCYCLIC AROMATIC HYDROCARBONS

2021 ◽  
Vol 0 (1) ◽  
pp. 56-65
Author(s):  
M.G. FAYZULLIN ◽  
◽  
E.YU. PANKRATYEV ◽  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Dipole Moment ◽  
Aromatic Hydrocarbons ◽  
Radical Cations ◽  
Microwave Spectrum ◽  
Neutral Molecule ◽  
Radical Anions ◽  
Radical Ions ◽  
Rotational Spectra ◽  
Polycyclic Aromatic

A theoretical study of the rotational spectra of a number of polycyclic aromatic hydrocarbons (PAHs) was carried out on the basis of quantum-chemical calculations by PRIRODA program in the PBE/3ζ approximation. Calculations are given for neutral molecules, their radical anions and radical cations in the rigid top approximation. Twelve neutral PAHs under study have no dipole moment and are not of interest for rotational spectroscopy. Thirteen neutral PAHs have a dipole moment not exceeding 0.09 Debye and, under certain conditions, can be studied in the microwave region. The remaining six compounds are PAHs with methyl and phenyl substituents, their dipole moments are 0.32-0.65 Debye, which makes it possible to study their microwave spectrum. For radical ions, the situation with the dipole moment is as follows: if a neutral molecule does not have a dipole moment, then the corresponding radical ion does not have it either; if the dipole moment of a neutral molecule is nonzero, then for radical ions it increases at least several times. For example, in the benzo [b] chrysene radical anion, the μa-component component of the dipole moment increases by 250 times, the μb-component by 7 times, and the total dipole moment by about 100 times. This effect is more pronounced for radical anions than for radical cations. In this case, it becomes possible to detect the spectrum of if not a neutral molecule, then at least one of its charge states. For a number of compounds, the patterns of various spectroscopic parameters depending on the number of carbon atoms in PAHs were found. In the B3LYP/6-31G(d,p) approximation, quartic centrifugal distortion constants were calculated for five compounds, and their effect on the rotational spectrum was estimated: for many compounds under study, they can have a significant effect on the microwave spectrum. With an increase in PAHs, the centrifugal constants decrease indicating an increase in the rigidity of the molecules. Thus, substituted neutral PAHs, as well as a number of radical ions, may be of interest for experimental studies in laboratory conditions and in space.

scholarly journals Extractive purification of hydro-treated gas oil with N-methylpyrrolidone

2017 ◽  
Vol 82 (1) ◽  
pp. 107-116
Author(s):  
Kahina Bedda ◽  
Boudjema Hamada ◽  
Nikolay Kuzichkin ◽  
Kirill Semikin
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Nitrogen Content ◽  
Aromatic Hydrocarbons ◽  
Diesel Fuel ◽  
Liquid Extraction ◽  
Gas Oil ◽  
Experimental Conditions ◽  
Clean Diesel ◽  
Liquid Liquid Extraction ◽  
Polycyclic Aromatic

The purification of a hydrotreated gas oil by liquid-liquid extraction with N-methylpyrrolidone as solvent has been studied. The results showed that this method, under appropriate experimental conditions, has reduced sulphur content of the gas oil from 174 ppm to 28 ppm, nitrogen content has decreased from 58 ppm to 15 ppm, aromatics content has diminished from 27.1 % to 13.8 % and the polycyclic aromatic hydrocarbons were totally extracted. The refined gas oil obtained can be used to produce clean diesel fuel for the environment.

scholarly journals Luminescent Molecular Switches Based on Dicationic P-Doped Polycyclic Aromatic Hydrocarbons

2020 ◽  
Author(s):  
Thomas Delouche ◽  
Antoine Vacher ◽  
Thierry Roisnel ◽  
Marie Cordier ◽  
Jean-Frederic Audibert ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Radical Cations ◽  
Molecular Switches ◽  
Fine Tuning ◽  
Efficient Synthesis ◽  
Paramagnetic Resonance ◽  
Polycyclic Aromatic ◽  
Electron Paramagnetic

We report the efficient synthesis of electron-acceptors based on cationic P-doped PAHs (Polycyclic Aromatic Hydrocarbons). Both endo- and exo-skeletal modifications of the p-core allow fine-tuning their optical and redox properties. Combined experimental (spectrolectrochemical and Electron Paramagnetic Resonance) and theoretical studies provide an in-depth characterization of the reduced species and specifically of the stable radical cations formed. Finally, electrochemical modulation of fluorescence highlights the potential of these intrinsically switchable electroactive fluorophores.

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