Solvent-induced chemical shifts in sterically hindered polynuclear aromatic hydrocarbons

1969 ◽  
pp. 876 ◽  
Author(s):  
K. D. Bartle ◽  
D. W. Jones ◽  
R. S. Matthews
Keyword(s):  
Aromatic Hydrocarbons ◽  
Chemical Shifts ◽  
Polynuclear Aromatic Hydrocarbons ◽  
Sterically Hindered

Multi-alkylated Polynuclear Aromatic Hydrocarbons of Tobacco Smoke: Separation and Identification

1978 ◽  
Vol 9 (4) ◽  
Author(s):  
M. E. Snook ◽  
R. F. Severson ◽  
R. F. Arrendale ◽  
H. C. Higman ◽  
O. T. Chortyk
Keyword(s):  
Liquid Chromatography ◽  
Cigarette Smoke ◽  
Aromatic Hydrocarbons ◽  
Ultra Violet ◽  
Polynuclear Aromatic Hydrocarbons ◽  
Gel Chromatography ◽  
Cigarette Smoke Condensate ◽  
Gas And Liquid Chromatography ◽  
Silicic Acid Chromatography ◽  
Derivatives Of

AbstractThe methyl, multi-methyl, and ethyl derivatives of the polynuclear aromatic hydrocarbons (PAH) of cigarette smoke condensate (CSC) were isolated from the neutrals by silicic acid chromatography, solvent partitioning and gel chromatography. The procedure yielded a relatively pure PAH isolate amenable to further identifications. The multi-alkylated PAH were concentrated in the early gel fractions with parent and higher ring PAH found in subsequent gel fractions. It was shown that CSC is very rich in alkylated PAH, and their successful identification required extensive use of gas and liquid chromatography and ultra-violet and GC - mass spectrometric techniques. High-pressure liquid chromatography (HPLC) separated individual isomers of the alkylated PAH in complex GC peaks. PAH from indene to pentamethylchrysene were found. This report concludes our identification studies on the PAH of CSC and complements our two previous reports in this journal. Collectively, our studies have identified approximately 1000 PAH of cigarette smoke condensate and have led to the development of methods for the routine quantitation of PAH in smalI quantities of cigarette smoke condensate.

Spectrophotometry Measurement of Polynuclear Aromatic Hydrocarbons in Hamilton Harbour Sediments

1991 ◽  
Vol 26 (1) ◽  
pp. 1-16 ◽  
Author(s):  
T.P. Murphy ◽  
H. Brouwer ◽  
M.E. Fox ◽  
E. Nagy
Keyword(s):  
Aromatic Hydrocarbons ◽  
Total Concentration ◽  
Coal Tar ◽  
Sediment Cores ◽  
Polynuclear Aromatic Hydrocarbons ◽  
Mass Spectrometry Analysis ◽  
Gas Chromatography Mass Spectrometry ◽  
Near Surface ◽  
Spectrometry Analysis ◽  
Hamilton Harbour

Abstract Eighty-one sediment cores were collected to determine the extent of coal tar contamination in a toxic area of Hamilton Harbour. Over 800 samples were analyzed by a UV spectrophotometric technique that was standardized with gas chromatography/mass spectrometry analysis. The coal tar distribution was variable. The highest concentrations were near the Stelco outfalls and the Hamilton-Wentworth combined sewer outfalls. The total concentration of the 16 polynuclear aromatic hydrocarbons (PAHs) in 48,300 m3 of near-surface sediments exceeded 200 µg/g.

Charge transfer energies of the complexes of (dibenzoylmethanato)boron difluoride with indeno-pyridines and polynuclear aromatic hydrocarbons

2013 ◽  
Vol 108 ◽  
pp. 181-185 ◽  
Author(s):  
Tandrima Chaudhuri ◽  
Sneha Salampuria ◽  
Pradip Kumar Tapaswi ◽  
Chhanda Mukhopadhyay ◽  
Subrata Chattopadhyay ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Aromatic Hydrocarbons ◽  
Polynuclear Aromatic Hydrocarbons ◽  
Boron Difluoride

scholarly journals Exploitation of Baird Aromaticity and Clar’s Rule for Tuning the Triplet Energies of Polycyclic Aromatic Hydrocarbons

Chemistry ◽  
2021 ◽  
Vol 3 (2) ◽  
pp. 532-549
Author(s):  
Felix Plasser
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Excited States ◽  
Aromatic Hydrocarbons ◽  
Density Functional ◽  
Materials Science ◽  
Chemical Shifts ◽  
Qualitative Description ◽  
Triplet States ◽  
Excitation Energies ◽  
Polycyclic Aromatic

Polycyclic aromatic hydrocarbons (PAH) are a prominent substance class with a variety of applications in molecular materials science. Their electronic properties crucially depend on the bond topology in ways that are often highly non-intuitive. Here, we study, using density functional theory, the triplet states of four biphenylene-derived PAHs finding dramatically different triplet excitation energies for closely related isomeric structures. These differences are rationalised using a qualitative description of Clar sextets and Baird quartets, quantified in terms of nucleus independent chemical shifts, and represented graphically through a recently developed method for visualising chemical shielding tensors (VIST). The results are further interpreted in terms of a 2D rigid rotor model of aromaticity and through an analysis of the natural transition orbitals involved in the triplet excited states showing good consistency between the different viewpoints. We believe that this work constitutes an important step in consolidating these varying viewpoints of electronically excited states.

Extraction of low molecular weight polynuclear aromatic hydrocarbons from ashes of coal-operated power plants

1987 ◽  
Vol 59 (17) ◽  
pp. 2066-2069 ◽  
Author(s):  
Filippo. Mangani ◽  
Achille. Cappiello ◽  
Giancarlo. Crescentini ◽  
Fabrizio. Bruner ◽  
Loretta. Bonfanti
Keyword(s):  
Molecular Weight ◽  
Aromatic Hydrocarbons ◽  
Power Plants ◽  
Polynuclear Aromatic Hydrocarbons ◽  
Low Molecular Weight

Application of SPME in the Analysis of Polynuclear Aromatic Hydrocarbons in Water by HPLC with DAD Detection

2001 ◽  
Vol 19 (1-4) ◽  
pp. 227-239 ◽  
Author(s):  
Vitor Vale Cardoso ◽  
Alexandre Rodrigues ◽  
Judite Correia ◽  
Maria João Benoliel
Keyword(s):  
Aromatic Hydrocarbons ◽  
Polynuclear Aromatic Hydrocarbons
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