Photophysics of polycyclic aromatic hydrocarbons adsorbed on silica gel surfaces. 3. Fluorescence quantum yields and radiative decay rate constants derived from lifetime distributions

1993 ◽  
Vol 97 (22) ◽  
pp. 5995-6001 ◽  
Author(s):  
Yuan S. Liu ◽  
Paul de Mayo ◽  
William R. Ware
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Decay Rate ◽  
Aromatic Hydrocarbons ◽  
Rate Constants ◽  
Radiative Decay ◽  
Quantum Yields ◽  
Lifetime Distributions ◽  
Radiative Decay Rate ◽  
Fluorescence Quantum Yields ◽  
Polycyclic Aromatic

Determination of Polycyclic Aromatic Hydrocarbons in the Presence of Humic Acid in water

2016 ◽  
Vol 70 (9) ◽  
pp. 1520-1528 ◽  
Author(s):  
Ruifang Yang ◽  
Nanjing Zhao ◽  
Xue Xiao ◽  
Shaohui Yu ◽  
Jianguo Liu ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Humic Acid ◽  
Aromatic Hydrocarbons ◽  
Fluorescence Quantum Yield ◽  
Quantum Yields ◽  
Fluorescence Quantum Yields ◽  
Polycyclic Aromatic ◽  
Pahs Concentration ◽  
Test Sets

The presence of humic acid (HA) makes it extremely difficult to determine and quantify accurately polycyclic aromatic hydrocarbons (PAHs) in aquatic environment because of their complex and strong interaction. To solve this problem, a new method was developed in this work through the combination of PARAFAC and fluorescence spectroscopy, which mainly includes: (1) the fluorescence quantum yield acquisition of PAHs with and without HA by PARAFAC; (2) the  concentration score correction of PAHs in validation and test sets using the fluorescence quantum yields; and (3) the prediction of PAHs concentration in the validation and test sets in the presence of HA by corrected concentration. Using this method, the PAHs concentration on the level of µg L−1 in the test samples with HA of 2.5 mg/L and 5.0 mg/L can be successfully predicted with the root mean square error below 0.15 µg L−1, relative error of prediction below 4% for validation samples, recoveries of each PAH between 82.5% and 102.6% for test samples.

scholarly journals Exploration of minimum energy conical intersection structures of small polycyclic aromatic hydrocarbons: toward an understanding of the size dependence of fluorescence quantum yields

2015 ◽  
Vol 17 (35) ◽  
pp. 22561-22565 ◽  
Author(s):  
Yu Harabuchi ◽  
Tetsuya Taketsugu ◽  
Satoshi Maeda
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Energy Barrier ◽  
Size Dependence ◽  
Minimum Energy ◽  
Conical Intersection ◽  
Quantum Yields ◽  
Fluorescence Quantum Yields ◽  
Polycyclic Aromatic

A correlation between the fluorescence quantum yields and the energy barrier to the conical intersection region was discovered for five small PAHs.

Fluorescence behaviour of some 4-substituted halobenzenes

1985 ◽  
Vol 50 (8) ◽  
pp. 1753-1763 ◽  
Author(s):  
Bohumír Koutek ◽  
Lubomír Musil ◽  
Jiří Velek ◽  
Milan Souček
Keyword(s):  
Decay Rate ◽  
Radiative Decay ◽  
Mean Value ◽  
Quantum Yields ◽  
Intersystem Crossing ◽  
Radiative Decay Rate ◽  
Fluorescence Quantum Yields ◽  
Band Position ◽  
Fluorescence Characteristics ◽  
Acetonitrile Solutions

The fluorescence characteristics of 4-substituted chloro and fluorobenzenes I and II were studied in isooctane and acetonitrile solutions. It was found that all compounds exhibit a weak (substituent and solvent dependent) fluorescence in the range 305-370 nm with quantum yields 1.2 . 10-2-2.3 . 10-1. The relation between the substituent nature and fluorescence band position may be quantified by log νf~ = ρσp + log νf~0, the magnitude of the shift paralleling the donor strength of the substituent. Fluorescence quantum yields are increased approximately by a factor 2 on going from isooctane to acetonitrile and solvent-induced shifts are proportional to the static dipole moment change Δμ which occurs upon excitation. Radiative decay rate varies only slightly around a mean value of 5 . 107 s-1 and shows no substantial difference between chloro (I) and fluoro (II) derivatives. The non-radiative decay rate (of the order ~ 109 s-1) was found to be about 5 times higher in the case of chloro compounds due to the more efficient S1 - Tn intersystem crossing.

Benzannulated Isobenzofurans

1988 ◽  
Vol 41 (2) ◽  
pp. 235 ◽  
Author(s):  
John Moursounidis ◽  
Dieter Wege
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Maleic Anhydride ◽  
Aromatic Hydrocarbons ◽  
Rate Constants ◽  
Diels Alder ◽  
Furan Series ◽  
Structure Count ◽  
Polycyclic Aromatic

A number of arynes, generated by treatment of haloarenes with sodium or potassium amide in tetrahydrofuran, were trapped with furan. The resulting dihydro epoxy arenes were converted into the following annulated isobenzofuran derivatives by using reverse Diels-Alder methodology: naphtho[l,2-clfuran, phenanthro[9,10-elfuran, pyreno[l,2-elfuran, pyreno[3,4- elfuran, anthra[l,2- elfuran, phenanthro[l,2- clfuran and phenanthro[3,4- elfuran. Bimolecular rate constants for the addition of maleic anhydride to these furans were measured, and were correlated with the Herndon structure count. Addition of arynes to selected members of this furan series yielded adducts which were deoxygenated to afford polycyclic aromatic hydrocarbons.

Reaction kinetics of hydrogen abstraction from polycyclic aromatic hydrocarbons by H atoms

2017 ◽  
Vol 19 (45) ◽  
pp. 30772-30780 ◽  
Author(s):  
Dingyu Hou ◽  
Xiaoqing You
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Reaction Kinetics ◽  
Aromatic Hydrocarbons ◽  
Rate Constants ◽  
Hydrogen Abstraction ◽  
Polycyclic Aromatic ◽  
Kinetics Of

We studied how the PAH structure, site, and size affect the rate constants of hydrogen abstraction reactions of PAH systematically.

QSARs on the Depuration Rate Constants of Polycyclic Aromatic Hydrocarbons inElliptio complanata

2009 ◽  
Vol 28 (5) ◽  
pp. 537-541 ◽  
Author(s):  
Dan Wu ◽  
Xinhui Liu ◽  
Lei Wang ◽  
Liang Wang ◽  
Mingzhu Xu ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Rate Constants ◽  
Polycyclic Aromatic ◽  
Depuration Rate
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