Spectroscopic Investigation of Polycyclic Aromatic Hydrocarbons Trapped in Liquid Helium Clusters

2003 ◽  
Author(s):  
Friedrich Huisken
1992 ◽  
Vol 46 (8) ◽  
pp. 1260-1265 ◽  
Author(s):  
Sheryl A. Tucker ◽  
Hardjanti Darmodjo ◽  
William E. Acree ◽  
John C. Fetzer ◽  
Maximilian Zander

Nitromethane is examined as a selective quenching agent for discriminating between “alternant” versus “nonalternant” polycyclic aromatic hydrocarbons in unknown mixtures. Of the 36 benzenoid solutes studied, only dibenzo[hi,wx]heptaphene failed to obey the selective quenching rule. Also reported are new experimental fluorescence probe studies for dibenzo[de,st]pentacene, dibenzo[fg,qr]pentacene, naphtho[8,1,2hij)-hexaphene, benzo[vwx]hexaphene, benzo[1,2,3cd;4,5,6c'd‘]diperylene, dibenzo[hi,wx]heptacene, benzo[b]triphenylene, chrysense, and anthracene dissolved in nonelectrolyte solvents of varying polarity. Benzo-[vwx]hexaphene was found to exhibit probe character, as evidenced by a systematic variation in emission intensity ratio with solvent polarity.


1992 ◽  
Vol 46 (7) ◽  
pp. 1156-1161 ◽  
Author(s):  
Vicki L. Amszi ◽  
Yvonne Cordero ◽  
Bradley Smith ◽  
Sheryl A. Tucker ◽  
William E. Acree ◽  
...  

Nitromethane is examined as a selective fluorescence quenching agent for “alternant” alkyl-substituted polycyclic aromatic hydrocarbons (PAHs). Fluorescence emission behavior is reported for 11 H-benz[bc]aceanthrylene, 4 H-cyclopenta[def]phenanthrene, 4 H-cyclopenta[def]chrysene, 13 H-dibenzo[a,g]fluorene, 13 H-dibenzo[a,i]fluorene, 4 H-benzo[b]cyclopenta[mno]chrysene, 4 H-cyclopenta[pqr]picene, 7 H-dibenzo[c,g]fluorene, 9 H-benz(6,7)indeno[1,21]phenanthrene, 4 H-benzo[b]cyclopenta[jkl]triphenylene, 13 H-dibenz[bc,k]aceanthrylene, 13 H-dibenz[bc,l]aceanthrylene, and 4 H-benzo[def]cyclopenta[mno]chrysene dissolved in organic solvents of varying polarity and in acetonitrile or aqueous-acetonitrile solvent mixtures at various nitromethane concentrations. Results of these measurements show that nitromethane quenches fluorescence emission of the thirteen solutes studied, which is in complete agreement with what would be expected on the basis of the fact that all solutes are “alternant” polycyclic aromatic hydrocarbons.


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

2019 ◽  
Author(s):  
Yachu Du ◽  
Kyle Plunkett

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>


2019 ◽  
Author(s):  
Yachu Du ◽  
Kyle Plunkett

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>


Author(s):  
M. Assad ◽  
V. V. Grushevski ◽  
O. G. Penyazkov ◽  
I. N. Tarasenko

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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