Quenching kinetics of the acridine excited state by vinyl monomers in homogeneous and micellar solution

Buchviser, Silmara F.; Gehlen, Marcelo Henrique

doi:10.1039/a605032h

Cited by 19 publications

(25 citation statements)

References 2 publications

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“…Pyrene fluorescence decays were measured by the singlephoton counting technique using a CD-900 Edinburgh spectrometer operating with a hydrogen-filled nanosecond flash lamp at 40-kHz pulse frequency (25). Time-resolved anisotropy measurements of Nile blue in micelles were performed with the same spectrometer equipped with Glan-Thompson polarizers, but the light pulse was provided by a 633-nm diode laser system (Hamamatsu Model PLP 01) with a pulse width of about 80 ps.…”

Section: Methodsmentioning

confidence: 99%

The Change in the Properties of Sodium Dodecyl Sulfate Micelles upon Addition of Isomeric and Unsaturated Short-Chain Alcohols Probed by Photophysical Methods

Romani

Gehlen

Lima

et al. 2001

Journal of Colloid and Interface Science

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Section: Methodsmentioning

confidence: 99%

The Change in the Properties of Sodium Dodecyl Sulfate Micelles upon Addition of Isomeric and Unsaturated Short-Chain Alcohols Probed by Photophysical Methods

Romani

Gehlen

Lima

et al. 2001

Journal of Colloid and Interface Science

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“…The photophysics of the tautomeric forms, which remain in dynamic protonation equilibrium with each other, is prone to environmental perturbations. [29][30][31][32][33][34] We tried to exploit this particular behavior of Acr to study its interactions with Ade and the nucleoside d-Ade by various time-resolved absorption and fluorescence measurements. We studied the protonation kinetics of the individual bases in an indirect fashion by observing their influence on the changes in protonation equilibrium and deprotonation rate of AcrH + .…”

mentioning

confidence: 99%

Influence of 2′‐Deoxy Sugar Moiety on Excited‐State Protonation Equilibrium of Adenine and Adenosine with Acridine inside SDS Micelles: A Time‐Resolved Study with Quantum Chemical Calculations

2012

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The protonation dynamics of the DNA base adenine (Ade) and its nucleoside 2'-deoxyadenosine (d-Ade) are investigated by monitoring the deprotonation kinetics of an N-heterocyclic DNA intercalator, acridine (Acr), in the confined environment of sodium dodecyl sulfate (SDS) micelles. Protonation of acridine (AcrH(+)) occurs at the hydrophilic interface and this species remains in dynamic equilibrium with its deprotonated counterpart (Acr) inside the hydrophobic core of SDS micelles. Quenching of the fluorescence of AcrH(+)* at 478 nm is observed after addition of Ade and d-Ade with Stern-Volmer constant (K(SV)) 298 and 75 M(-1), respectively, with a concomitant increment in Acr* at 425 nm. Time-resolved fluorescence studies reveal quenching in the lifetime of AcrH(+)*. The relative amplitude of AcrH(+)* decreases from 0.97 to 0.51 and 0.97 to 0.89 with equimolar addition of Ade and d-Ade, respectively. These observations are explained by excited-state proton transfer (ESPT) from AcrH(+)* to the bases. The reduced K(SV) value and negligible change in the relative amplitudes of AcrH(+)* with d-Ade infer that ESPT is hindered substantially by the presence of a 2'-deoxy sugar unit. Transient time-resolved absorption spectra of Acr reflect that Ade reduces the absorbance of (3)AcrH(+)*; however, d-Ade keeps it unaltered for more than a time delay of 2 μs. The optimized geometries calculated by quantum chemical methods reflect deprotonation of AcrH(+)* with protonation at the N1 position of Ade, while it remains protonated with d-Ade. The hindered ESPT between AcrH(+)* and d-Ade singles out the significance of the 2'-deoxy sugar moiety in controlling the deprotonation kinetics.

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“…Buchviser et al by steady-state and time-resolved fluorescence reported the formation of AcrH + inside heterogeneous environment of both SDS micelles and reverse micelles. 44 The formation of AcrH + at the interfacial hydrophilic region of the SDS micelles and its equilibrium with Acr* have also been reported in the literature. 54 In micellar systems, three domains can be defined: the hydrophilic or aqueous domain, the hydrophobic domain formed by the surfactant alkyl chains, and the micellar interface.…”

Section: ■ Results and Discussionmentioning

confidence: 87%

Prototropic Interactions of Pyrimidine Nucleic Acid Bases with Acridine: A Spectroscopic Investigation

2012

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In this article, we have investigated the interactions of three pyrimidine nucleic acid bases, cytosine (C), thymine (T), and uracil (U) with acridine (Acr), an N-heterocyclic DNA intercalator, through the changes in photophysics of Acr inside SDS micelles. Fluorescence of AcrH(+)* at 478 nm and its lifetime are quenched on addition of C, T, and U, while a concomitant increment of Acr* is observed only with C. However, the relative amplitude of Acr* increases with a simultaneous decrease in AcrH(+)* only with C. The fluorescence quenching of AcrH(+)* is explained by photoinduced electron transfer (PET), while changes in the relative contributions of Acr* and AcrH(+)* with C are due to associated excited-state proton transfer (ESPT). The rate of electron transfer (kET) is maximum for T, followed by U and C. The associated ESPT from AcrH(+)* is the reason behind the reduced efficiency of PET with C. The lack of proton transfer with T and U as well as the higher kET for T compared to U are explained by keto-enol tautomerization and subtle changes in the structure and geometry of the pyrimidine bases.

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Quenching kinetics of the acridine excited state by vinyl monomers in homogeneous and micellar solution

Cited by 19 publications

References 2 publications

The Change in the Properties of Sodium Dodecyl Sulfate Micelles upon Addition of Isomeric and Unsaturated Short-Chain Alcohols Probed by Photophysical Methods

The Change in the Properties of Sodium Dodecyl Sulfate Micelles upon Addition of Isomeric and Unsaturated Short-Chain Alcohols Probed by Photophysical Methods

Influence of 2′‐Deoxy Sugar Moiety on Excited‐State Protonation Equilibrium of Adenine and Adenosine with Acridine inside SDS Micelles: A Time‐Resolved Study with Quantum Chemical Calculations

Prototropic Interactions of Pyrimidine Nucleic Acid Bases with Acridine: A Spectroscopic Investigation

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