Effect of pressure on the external heavy atom quenching of pyrene fluorescence in fluid solution

Okamoto, Masami; Teranishi, Hiroshi

doi:10.1021/j150667a037

Cited by 29 publications

(26 citation statements)

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“…17 The concentration of DMEA for the Ñuorescence lifetime measurements was less than 0.1 (1 cm cell) in absorbance at maximum absorption wavelength in order to minimize the reabsorption e †ects. The Ñuorescence intensities were measured by a Hamamatsu R1635-02 photomultiplier through a Ritsu MC-25NP monochromator, and the resulting signal was digitized by using a LeCroy 9362 digitizing oscilloscope.…”

Section: Introductionmentioning

confidence: 99%

Temperature dependence of the nearly diffusion-controlled fluorescence quenching by oxygen of 9,10-dimethylanthracence in liquid solution

Okamoto

2001

Phys. Chem. Chem. Phys.

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The rate constant, for the Ñuorescence quenching of 9,10-dimethyl-anthracene (DMEA) by oxygen in k q , n-hexane and methylcyclohexane (MCH) was measured as a function of temperature at 0.1 MPa. It was found that the activation energy for the quenching, was 6.6^0.1 and 8.4^0.3 kJ mol~1, smaller than that for E q E, the solvent viscosity, 7.1^0.2 and 10.6^0.1 kJ mol~1, in n-hexane and MCH, respectively. The E i E, di †erence between and was interpreted to arise as a result of the quenching being not fully but nearly E q E E i E di †usion-controlled. The contribution of di †usion to the quenching was analyzed quantitatively from the temperature dependence of the solvent viscosity together with that of the radial distribution function at the closest approach distance with hard spheres. The results were shown to be consistent with those obtained from the high-pressure study reported previously.

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Section: Introductionmentioning

confidence: 99%

Temperature dependence of the nearly diffusion-controlled fluorescence quenching by oxygen of 9,10-dimethylanthracence in liquid solution

Okamoto

2001

Phys. Chem. Chem. Phys.

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“…20 A nitrogen laser (337.1 nm/8 ns pulse width) was used as the excitation light source. The luminescence intensities were measured at right angles to the direction of the exciting light by use of a Hamamatsu R 928 photomultiplier through a Ritsu MC-25NP monochromator.…”

Section: Methodsmentioning

confidence: 99%

Dynamic Quenching of Luminescence in Reversed Micelles under High Pressure

Okamoto

1996

J. Phys. Chem.

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Dynamic quenching of luminescence of tris(2,2′-bipyridyl)ruthenium(II) chloride by potassium hexacyanoferrate(III) in the sodium bis(2-ethylhexyl)sulfosuccinate (AOT)/water/heptane reversed micellar system was studied as a function of pressure from 0.1 to 300 MPa at 25°C. From the analysis of the decay curves in solutions with W 0 ()[H 2 O]/[AOT]) of 10.3, 14.0, and 22.0, it was found that the quenching rate constants, k q , in micelles were decreased significantly with increasing pressure, while the rate constants, k ex , for the quencher exchange by collision between micelles were found to increase strongly with increasing pressure. The activation volumes for k q were almost independent of W 0 (16 cm 3 /mol), and those for k ex were decreased monotonically from -24 (W 0 ) 10.3) to -54 cm 3 /mol (W 0 ) 22.0) depending on W 0 . From the results of the pressure dependence of k q , the microenvironment inside the micelles is discussed. The largely negative activation volumes for k ex are interpreted on the basis of an encounter or a collision complex formation between micelles prior to the quencher exchange, whose dissociative backward process exhibits larger pressure dependence than the forward one.

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“…It is noteworthy that the fluorescent response of the N-alkylpyridinium triflate salt 2b was 2.3 fold greater than the corresponding iodide salt 2a, which we ascribed to the known heavy atom quenching effect of the iodide counter ion. 19 Whilst alkylation of pyridine 1 with the potent triflate/iodide alkylating agents 3a-c gave an almost instantaneous increase in fluorescence (seconds), use of alkyl bromides 3d-k required a longer time (hours) to react before solutions with stable fluorescence maxima were obtained. The corresponding control experiments where pyridine and benzene with and without added methyl iodide had previously confirmed an intramolecular interaction is responsible for the observed fluorescence.…”

Section: And Esiw)mentioning

confidence: 99%

“…1). 19 In order to determine the detection limits of this sensor we reduced the concentration of pyridine 1 to 0.01 mM in CH 2 Cl 2 and assayed its fluorescent response to the presence of low concentrations of methyl iodide (0-400 nM). This resulted in a three fold increase in fluorescence over a concentration range of 0-400 nM, with a lower detection limit for methyl iodide of 1 nM (see Fig.…”

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confidence: 99%

A pyridinium cation–π interaction sensor for the fluorescent detection of alkyl halides

et al. 2011

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Effect of pressure on the external heavy atom quenching of pyrene fluorescence in fluid solution

Cited by 29 publications

References 1 publication

Temperature dependence of the nearly diffusion-controlled fluorescence quenching by oxygen of 9,10-dimethylanthracence in liquid solution

Temperature dependence of the nearly diffusion-controlled fluorescence quenching by oxygen of 9,10-dimethylanthracence in liquid solution

Dynamic Quenching of Luminescence in Reversed Micelles under High Pressure

A pyridinium cation–π interaction sensor for the fluorescent detection of alkyl halides

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