Singlet-quenching of photoexcited aromatics by carbonyl compounds

Busch, Deborah; Dahm, Lisa; Siwicke, Brian; Ricci, Robert W.

doi:10.1016/s0040-4039(01)83545-0

Cited by 8 publications

(4 citation statements)

References 11 publications

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“…In order to check the possible charge transfer origin of these complexes, we tried to correlate the equilibrium constants with the half-wave reduction potentials of the perturber molecules which are known for CC14, CHC13, CH2C12, and C3H7Br.26,27 To estimate the free energy change accompanying charge transfer quenching, Ricci et al 28 have proposed the following relation AG = £V2(D+/D) -AjEoo(D) -El/2{Ar/A) -e02/r (23) where the first term is the oxidation potential of the donor, the second term is the excitation energy of the donor, the third term is the reduction potential of the acceptor, and the last term is the free energy gained by bringing the ions to the encounter distance r. By making the assumption that all terms are constants but the third one, a linear relationship should exist between log K and E1/2(A~/A).…”

Section: Kinetic Analysismentioning

confidence: 99%

Singlet and triplet quenching of indole by heavy atom containing molecules in a low temperature glassy matrix. Evidence for complexation in the triplet state

Lessard¹,

Durocher²

1978

J. Phys. Chem.

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Section: Kinetic Analysismentioning

confidence: 99%

Singlet and triplet quenching of indole by heavy atom containing molecules in a low temperature glassy matrix. Evidence for complexation in the triplet state

Lessard¹,

Durocher²

1978

J. Phys. Chem.

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“…DA, l -DOPA, and NE are known to be electroactive at modest potentials, readily oxidizing to a carbonyl-containing ortho -quinone in solution. Ricci and co-workers have previously shown that carbonyls are capable of quenching excited state aromatic rings via the formation of excited-state complexes; , a similar process is likely occurring in this system. To prevent the formation of ortho -quinones, perchloric or ascorbic acid has historically been added to samples to prevent oxidation in solution prior to analysis. , Here, ascorbic acid was added to the derivatization reaction, and fluorescence was again monitored over time (Figure B, red dashed traces).…”

Section: Resultsmentioning

confidence: 70%

To Fluoresce or Not to Fluoresce: Investigation of Structural and Fluorescence Characteristics of CBI-Dopamine, CBI-Serotonin, and Their Structural Analogs

Rigby,

Saylor

2023

Anal. Chem.

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Dopamine (DA) and serotonin (5-HT) are neurotransmitters that are vital for proper brain function and are implicated in a wide variety of diseases and disorders. Unfortunately, quantitative analysis of DA and 5-HT is difficult, as they are present at low concentrations in complex biological matrices. The fluorogenic reaction of napththalene-2,3-dicarboxaldehyde (NDA) with a primary amine in the presence of cyanide (CN) creates an N-substituted 1-cyanobenz[f]isoindole (CBI) derivative, whose fluorescence can be sensitively monitored in biological matrices. Given their biological importance, there are surprisingly few reports showing fluorescence of CBI-DA and no prior publications concerning CBI-5-HT. In this work, nuclear magnetic resonance spectroscopy (NMR) was employed to determine the atom connectivity of over 10 CBI-products, including CBI-DA and CBI-5-HT. NMR and fluorescence spectroscopy were applied to CBI-DA, CBI-5-HT, and select structural analogs to determine structural correlations with the observed lack of fluorescence. Experiments with CBI-DA and structural analogs indicated fluorescence was rapidly quenched due to both complexation with the historically employed buffer and oxidation in solution. Fluorescence of CBI-DA was recovered by modifying the derivatization background to prevent complexation and oxidation. In contrast, fluorescence characterization of CBI-5-HT and its structural analogs indicated that 5-HT was acting as a quencher of the CBI-ring. The addition of acid to protonate 5-HT was found to disrupt this interaction and enable the first reported fluorescence detection of CBI-5-HT. In the future, this work will be applied to detect DA and 5-HT in biological systems to gain insight into neurobiological disease states and disorders.

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“…It probably occurs via the classic dipole-dipole non-radiative energy transfer described by Forster (1959), since cholesta-4,6-dien-3-one has a small absorption peak at about 375 nm that overlaps slightly with the emission peaks of the two probes. With conjugated carbonyl compounds such as the steroid, formation of a charge-transfer stabilized exciplex is also a possible mechanism (Busch et al, 1977). In solutions of donor and acceptor, quenching by either mechanism will obey Stern-Volmer kinetics (Shinitzky & Rivnay, 1977).…”

Section: Fluorescence Quenchingmentioning

confidence: 99%

Use of fluorescent probes in the study of phospholipid–sterol bilayers

Wharton¹,

Martinez²,

Green³

1980

Biochemical Journal

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1. The transfer of excitation energy between the fluorescent probes 1,6-diphenylhexa-1,3,5-triene and 12-(9-anthroyl)stearic acid and the cholesterol analogue cholesta-4,6-dien-3-one in phosphatidylcholine liposomes has been investigated. 2. The results indicate that probes and steroid are randomly distributed in the bilayer at steroid concentrations up to 35mol%. 3. The degree of polarization of diphenylhexatriene fluorescence increases with increasing cholesterol content. Other sterols, differing in structure in the region of the polar group or in the side chain at position-17, produce similar but not identical effects. 4. The results are consistent with the proposal that diphenylhexatriene gives a general picture of the state of the bilayer and that there is no segregation of sterols in liquid-crystalline phosphatidylcholine bilayers.

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Singlet-quenching of photoexcited aromatics by carbonyl compounds

Cited by 8 publications

References 11 publications

Singlet and triplet quenching of indole by heavy atom containing molecules in a low temperature glassy matrix. Evidence for complexation in the triplet state

Singlet and triplet quenching of indole by heavy atom containing molecules in a low temperature glassy matrix. Evidence for complexation in the triplet state

To Fluoresce or Not to Fluoresce: Investigation of Structural and Fluorescence Characteristics of CBI-Dopamine, CBI-Serotonin, and Their Structural Analogs

Use of fluorescent probes in the study of phospholipid–sterol bilayers

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