scholarly journals Polycyclic Aromatic Hydrocarbons with Straight Edges and the 7.6/6.2 and 8.6/6.2 Intensity Ratios in Reflection Nebulae

2018 ◽  
Vol 854 (2) ◽  
pp. 115 ◽  
Author(s):  
Alessandra Ricca ◽  
Charles W. Bauschlicher ◽  
Joseph E. Roser ◽  
Els Peeters
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Polycyclic Aromatic ◽  
Intensity Ratios ◽  
Reflection Nebulae

scholarly journals Spectroscopic Properties of Polycyclic Aromatic Hydrocarbons: Effect of Solvent Polarity on the Fluorescence Emission Behavior of Select Fluoranthene, Fluorenochrysene, Indenochrysene, and Indenopyrene Derivatives

1991 ◽  
Vol 45 (10) ◽  
pp. 1699-1705 ◽  
Author(s):  
Sheryl A. Tucker ◽  
William E. Acree ◽  
Bongsup P. Cho ◽  
Ronald G. Harvey ◽  
John C. Fetzer
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Fluorescence Emission ◽  
Solvent Polarity ◽  
Spectroscopic Properties ◽  
Effect Of Solvent ◽  
Polycyclic Aromatic ◽  
Organic Nonelectrolyte ◽  
Emission Behavior ◽  
Intensity Ratios

Fluorescence emission behavior is reported for benz[def]indeno-[1,2,3hi]chrysene, fluoreno[2,3,4,9defg]chrysene, benz[def]indeno-[l,2,3qr]chrysene, dibenzo[a,e]fluoranthene, indeno[1,2,3cd]pyrene, naphtho[1,2b]fluoranthene, benzo[b]fluoranthene, fluoranthene, benzo-[ghi]fluoranthene, naphtho[2,1a]fluoranthene, naphtho[2,3b]fiuoranthene, benzo[k]fluoranthene, and benzo[j]fluoranthene dissolved in organic nonelectrolyte solvents of varying polarity. Results of these measurements are used to classify the various solutes as either probe or nonprobe molecules, depending upon whether measured emission intensity ratios vary systematically with solvent polarity. Also discussed are primary and secondary inner-filtering artifacts associated with selective quenching agents used to help identify/analyze polycyclic aromatic hydrocarbons (PAHs) in unknown mixtures. Inner-filtering artifacts are illustrated by examining fluorescence emission intensities of 13 “nonalternant” PAHs at different nitromethane concentrations and solution absorbances.

The Assessment of Contamination and Source of Polycyclic Aromatic Hydrocarbons from the Sediments of the Someş River

2019 ◽  
Vol 64 (1) ◽  
pp. 55-67
Author(s):  
Vlad Pӑnescu ◽  
◽  
Mihaela Cӑtӑlina Herghelegiu ◽  
Sorin Pop ◽  
Mircea Anton ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Polycyclic Aromatic

1,1’-Biaceanthrylene and 2,2'-Biaceanthrylene: Models for Linking Larger Polycyclic Aromatic Hydrocarbons via Five-Membered Rings

2019 ◽  
Author(s):  
Yachu Du ◽  
Kyle Plunkett
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Polycyclic Aromatic Hydrocarbon ◽  
Aromatic Hydrocarbon ◽  
Electronic Properties ◽  
Aromatic Hydrocarbons ◽  
Model Systems ◽  
Redox Potentials ◽  
Dimer Model ◽  
Optical And Electronic Properties ◽  
Polycyclic Aromatic

We show that polycyclic aromatic hydrocarbon (PAH) chromophores that are linked between two five-membered rings can access planarized structures with reduced optical gaps and redox potentials. Two aceanthrylene chromophores were connected into dimer model systems with the chromophores either projected outward (2,2’-biaceanthrylene) or inward (1,1’-biaceanthrylene) and the optical and electronic properties were compared. Only the planar 2,2’-biaceanthrylene system showed significant reductions of the optical gaps (1 eV) and redox potentials in relation to the aceanthrylene monomer.<br>

1,1’-Biaceanthrylene and 2,2'-Biaceanthrylene: Models for Linking Larger Polycyclic Aromatic Hydrocarbons via Five-Membered Rings

2019 ◽  
Author(s):  
Yachu Du ◽  
Kyle Plunkett
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Polycyclic Aromatic Hydrocarbon ◽  
Aromatic Hydrocarbon ◽  
Electronic Properties ◽  
Aromatic Hydrocarbons ◽  
Model Systems ◽  
Redox Potentials ◽  
Dimer Model ◽  
Optical And Electronic Properties ◽  
Polycyclic Aromatic

We show that polycyclic aromatic hydrocarbon (PAH) chromophores that are linked between two five-membered rings can access planarized structures with reduced optical gaps and redox potentials. Two aceanthrylene chromophores were connected into dimer model systems with the chromophores either projected outward (2,2’-biaceanthrylene) or inward (1,1’-biaceanthrylene) and the optical and electronic properties were compared. Only the planar 2,2’-biaceanthrylene system showed significant reductions of the optical gaps (1 eV) and redox potentials in relation to the aceanthrylene monomer.<br>

EMISSION OF POLYCYCLIC AROMATIC HYDROCARBONS CONTAINED IN COMBUSTION PRODUCTS OF GASOLINE ENGINES

2018 ◽  
Vol 62 (3) ◽  
pp. 341-346 ◽  
Author(s):  
M. Assad ◽  
V. V. Grushevski ◽  
O. G. Penyazkov ◽  
I. N. Tarasenko
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
High Speed ◽  
Internal Combustion Engines ◽  
Catalytic Converter ◽  
Combustion Products ◽  
Chromatography Method ◽  
Exhaust Gases ◽  
Polycyclic Aromatic ◽  
Load Mode

The concentration of 16 polycyclic aromatic hydrocarbons (PAHs) in the gasoline combustion products emitted into the atmosphere by internal combustion engines (ICE) has been measured using the gas chromatography method. The concentrations of PAHs in the exhaust gases sampled behind a catalytic converter has been determined when the ICE operates in five modes: idle mode, high speed mode, load mode, ICE cold start mode (engine warm-up) and transient mode. Using 92 RON, 95 RON and 98 RON gasoline the effect of the octane number of gasoline on the PAHs content in the exhaust gases has been revealed. The concentration of the most carcinogenic component (benzo(α)pyrene) in the exhaust gases behind a catalytic converter significantly exceeds a reference value of benzo(α)pyrene in the atmospheric air established by the WHO and the EU for ICE in the load mode.

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