Spectroscopic properties of polycyclic aromatic compounds

Tucker, Sheryl A.; Bates, Heather C.; Amszi, Vicki L.; Acree, William E.; Lee, Hongmee; Raddo, Pasquale Di; Harvey, Ronald G.; Fetzer, John C.; Dyker, Gerald

doi:10.1016/0003-2670(93)85109-w

Cited by 30 publications

(9 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Emission intensities * To whom correspondence should be addressed More recent measurements [9,10] revealed that nitromethane quenched fluorescence emission of all eighteen acenaphthylene-and acephenanthrylenederivatives studied thus far which is completely contrary to what would be expected based upon the fact that the solutes are listed as "textbook" examples of nonalternant PAH molecules. Solutes are classified as alternant PAHs if every alternant carbon atom in the aromatic ring system can be "starred".…”

mentioning

confidence: 46%

Examination of the nitromethane selective quenching rule in micellar anionic sodium dodecylbenzenesulfonate and micellar cationic dodecylethyldimethylammonium bromide solvent media

1998

Self Cite

View full text Add to dashboard Cite

Abstract. Applicability of the nitromethane selective quenching rule for discriminating between alternant versus nonalternant polycyclic aromatic hydrocarbons (PHAs) is examined for 38 representative PAH solutes dissolved in micellar sodium dodecylbenzenesulfonate (SDBS) and in micellar dodecylethyldimethylammonium bromide (DEDAB) solvent media. Experimental results show that nitromethane quenched fluorescence of only the 20 alternant PAHs in the cationic DEDAB surfactant solvent media as expected. Emission intensities of nonalternant PAHs, except for the few borderline cases noted in previous work, were unaffected by nitromethane addition. Unexpected quenching behavior was observed, however, in the case of nonalternant PAHs dissolved in micellar sodium dodecylbenzenesulfonate solvent media. Nitromethane quenched fluorescence emission of all 18 nonalternant PAHs studied in the SDBS solvent media, which is contrary to the selective quenching rule.Key words: fluorescence quenching, micellar solvent media, nitromethane selective quenching rule, anionic surfactants, cationic surfactants.This study continues a systematic examination of the effect that solvent media and substituent functional group has on the ability of nitromethane to selectively quench fluorescence emission of altemant polycyclic aromatic hydrocarbons (PAHs). Emission intensities * To whom correspondence should be addressed More recent measurements [9,10] revealed that nitromethane quenched fluorescence emission of all eighteen acenaphthylene-and acephenanthrylenederivatives studied thus far which is completely contrary to what would be expected based upon the fact that the solutes are listed as "textbook" examples of nonalternant PAH molecules. Solutes are classified as alternant PAHs if every alternant carbon atom in the aromatic ring system can be "starred". Nonalternant PAHs, on the other hand, would have at least one pair of adjacent starred atoms [11,12]. The unusual fluorescence quenching behavior of the acenaphthylene-and acephenanthrylene-derivatives results from the molecules' fixed double bond in the five-membered ring. The double bond is alkenic in nature, rather than aromatic as one might believe and should not be included as part of the aromatic ring system when determining whether the compound is an alternant versus nonalternant PAH. This observation is confirmed by independent NMR coupling measurements [13][14][15][16]. Moreover, for cyclopent[fg]acenaphthylene, where movement of the double bonds in the two cyclopenta-rings leads presumably to a valid fourth resonance structure, Freiermuth et al. [17]

show abstract

mentioning

confidence: 46%

Examination of the nitromethane selective quenching rule in micellar anionic sodium dodecylbenzenesulfonate and micellar cationic dodecylethyldimethylammonium bromide solvent media

1998

Self Cite

View full text Add to dashboard Cite

show abstract

“…One belonging to the alternant anthracene moiety that is quenched by selective quenching agents, such as nitromethane, and one belonging to the nonalternant fluoranthene moiety that is not quenched by nitromethane (17,23).…”

Section: Methodsmentioning

confidence: 99%

“…The PAHs, which have a fixed double bond in the five membered rings, have been classified as alternant and nonalternant PAHs in the literature (18,29,40). Nuclear Magnetic Resonance (NMR) data (45)(46)(47) and extensive selective quenching results (22,23,29) clearly suggest that an alternant classification for these compounds is most suitable.…”

Section: Listed Inmentioning

confidence: 98%

“…Therefore, these PAHs, pyrene and acenaphthylene, probably should be classified as borderline cases, rather than true exceptions to the diisopropylamine selective quenching rule. Also, solvent polarity is known to play a large part in the selective quenching phenomenon (21,23,36,38), and may be a factor in the anomalous pyrene results.…”

Section: Listed Inmentioning

confidence: 99%

“…Five additional PAHs, containing a fixed double bond in the cyclopenta ring ( Figure 1C), were also examined because their alternant-nonalternant classification is controversial (18,23,29,40). The selective quenching ability of diisopropylamine was also examined at a reduced pH because real-world HPLC samples may be acidic or examined under acidic conditions.…”

mentioning

confidence: 99%

See 2 more Smart Citations