Lifetime and quenching rate constant for the lowest triplet state of sulfur dioxide

1970 ◽  
Vol 92 (1) ◽  
pp. 217-218 ◽  
Author(s):  
Susan S. Collier ◽  
Akira. Morikawa ◽  
David H. Slater ◽  
Jack G. Calvert ◽  
George. Reinhardt ◽  
...  
Keyword(s):  
Sulfur Dioxide ◽  
Triplet State ◽  
Rate Constant ◽  
Quenching Rate ◽  
Quenching Rate Constant

Phenyl Substitution Effects on Triplet–Triplet Absorption Spectra: I. Study of 1,3,6,8-Tetraphenylpyrene

1975 ◽  
Vol 53 (21) ◽  
pp. 3269-3275 ◽  
Author(s):  
C. Rullière ◽  
E. C. Colson ◽  
P. C. Roberge
Keyword(s):  
Absorption Spectrum ◽  
Triplet State ◽  
Absorption Spectra ◽  
Rate Constant ◽  
Theoretical Calculations ◽  
Vibrational Structure ◽  
Substitution Effects ◽  
Quenching Rate ◽  
Diffusion Controlled ◽  
Quenching Rate Constant

The triplet–triplet (T–T) absorption spectrum of 1,3,6,8-tetraphenylpyrene (TPP) was measured from 400 to 620 nm. The data obtained are compared with theoretical calculations using the Ruedenberg–Scherr FEMO model. A planar triplet state is evidenced by fine vibrational structure. The T–T quenching rate constant measured (1.3 ± 0.1 × 109 M−1 s−1) is 20% of the expected diffusion-controlled value.

Temperature dependence of the O+I(P21/2)→O+I(P23/2) quenching rate constant

2009 ◽  
Vol 105 (9) ◽  
pp. 094911 ◽  
Author(s):  
Pavel A. Mikheyev ◽  
David J. Postell ◽  
Michael C. Heaven
Keyword(s):  
Temperature Dependence ◽  
Rate Constant ◽  
Quenching Rate ◽  
Quenching Rate Constant

Quenching rate constant for O(1S)+NO

1972 ◽  
Vol 1 (4) ◽  
pp. 341-344 ◽  
Author(s):  
R. Atkinson ◽  
K.H. Welge
Keyword(s):  
Rate Constant ◽  
Quenching Rate ◽  
Quenching Rate Constant

Solvent effect on the reactivity of monosubstituted phenols towards singlet molecular oxygen (O2(1Δg)) in alkaline media

1993 ◽  
Vol 71 (8) ◽  
pp. 1247-1252 ◽  
Author(s):  
Marta Luiz ◽  
María I. Gutiérrez ◽  
Graciela Bocco ◽  
Norman A. García
Keyword(s):  
Molecular Oxygen ◽  
Rate Constant ◽  
Reaction Pathway ◽  
Aqueous Media ◽  
Solvent Polarity ◽  
Alkaline Media ◽  
Quantum Yields ◽  
Quenching Rate ◽  
Singlet Molecular Oxygen ◽  
Quenching Rate Constant

The influence of solvent polarity on the dye-sensitized photooxidation (singlet molecular oxygen (O2(1Δg)) mediated) of a series of para-substituted phenolates was studied. Kinetic evidence obtained shows that the overall and the pure chemical interactions, phenolate–O2(1Δg), depend on the solvent polarity in a different way. This is clearly reflected in the efficiency of O2(1Δg) photooxidation of the substrates: surprisingly, the photooxidation quantum yield increases as the overall quenching rate constant decreases. The substrate photooxidation quantum yields obtained ranged from 0.05 to 0.15, the upper limit corresponding to a moderately polar medium (a benzene–methanol mixture) and the lower to an aqueous medium. We conclude that a high solvent polarity favours only the obtainment of the encounter complex (O2(1Δg)–phenolate), whereas the reactive step is affected in much the same way as those processes where charges are neutralized along the reaction pathway. The results obtained are discussed in terms of a partly polar excited state complex between O2(1Δg) and the phenolates. The rate constant for the reactive pathway in both organic and aqueous media is correlated with the Hammet-type substituent constant R−.

Oxygen sensing based on lifetime of photoexcited triplet state of platinum porphyrin-polystyrene film using time-resolved spectroscopy

2000 ◽  
Vol 04 (03) ◽  
pp. 292-299 ◽  
Author(s):  
YUTAKA AMAO ◽  
KEISUKE ASAI ◽  
ICHIRO OKURA
Keyword(s):  
Triplet State ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Oxygen Sensing ◽  
Laser Flash ◽  
Quenching Rate ◽  
Time Resolved ◽  
Quenching Rate Constant ◽  
Volmer Plot ◽  
Platinum Porphyrin

Optical oxygen-sensing systems based on the quenching of the photoexcited triplet state of platinum porphyrins—platinum octaethylporphyrin (PtOEP) and platinum tetrakis(pentafluorophenyl)porphyrin (PtTFPP)—in polystyrene (PS) using two different time-resolved spectroscopies (luminescence lifetime measurement and diffuse reflectance laser flash photolysis) have been developed. Using both spectroscopies, the same values of Stern-Volmer constant KSV and quenching rate constant kq (KSV = kqτ0) are obtained. The decays of the luminescence and triplet-triplet reflectance of the platinum porphyrins in PS consisted of two components (faster and slower lifetimes) in the absence and presence of oxygen. For both faster and slower components the lifetime decreases with increasing oxygen concentration. For both components a Stern-Volmer plot of the platinum porphyrin-PS films exhibits linearity. However, kq of the faster component is larger than that of the slower component (for PtOEP, three times larger; for PtTFPP, 40 times larger), indicating that two different oxygen-accessible sites exist in the platinum porphyrin-PS films. The faster and slower components are related to oxygen-accessible sites on the surface and in the bulk of the platinum porphyrin films respectively. Concerning the fractional contributions of each lifetime component, the contribution of the faster component is greater than that of the slower component, indicating that the sensing site on the surface is important for optical sensing. The contribution of different oxygen-accessible sites in platinum porphyrin-PS films for oxygen sensing is clarified by these techniques.

Radiative lifetime and quenching rate constant of AsF2* fluorescence

1989 ◽  
Vol 22 (16) ◽  
pp. 2527-2529 ◽  
Author(s):  
C Ye ◽  
M Suto ◽  
L C Lee ◽  
T J Chuang
Keyword(s):  
Rate Constant ◽  
Radiative Lifetime ◽  
Quenching Rate ◽  
Quenching Rate Constant

Solvent effects on the fluorescence quenching rate constant of an intramolecular exciplex by poly(chlorobenzenes)

1996 ◽  
Vol 92 (18) ◽  
pp. 3327 ◽  
Author(s):  
Carlos A. Chesta ◽  
Vicente Avila ◽  
Arnaldo T. Soltermann ◽  
Carlos M. Previtali ◽  
Juan J. Cosa ◽  
...  
Keyword(s):  
Fluorescence Quenching ◽  
Rate Constant ◽  
Solvent Effects ◽  
Quenching Rate ◽  
Quenching Rate Constant

Polyoligopeptides functionalized zinc(II)porphyrins: Step towards artificial hemes

2011 ◽  
Vol 15 (09n10) ◽  
pp. 871-882 ◽  
Author(s):  
Shawkat M. Aly ◽  
Hannah Guernon ◽  
Brigitte Guérin ◽  
Pierre D. Harvey
Keyword(s):  
Fluorescence Quenching ◽  
Click Chemistry ◽  
Computer Modeling ◽  
Rate Constant ◽  
Steric Hindrance ◽  
Rate Constants ◽  
Emission Spectra ◽  
Quenching Rate ◽  
Photophysical Parameters ◽  
Quenching Rate Constant

Two new zinc(II)porphyrin oligopeptide conjugates (zinc(II)-5,10,15,20-bis[4-(peptide)- phenyl]porphyrin (5) and -tetrakis[3,5-di(peptide)phenyl]porphyrin (9; peptide = -CH2(CO)Gly-Phe-Ala-CNH2) were prepared using the click chemistry with azides and ethynyl-containing precursors. The spectroscopic signature (S0→S1 and transient T1→Tn absorption, excitation and emission spectra) are typical for zinc(II)porphyrin and shows no perturbation upon anchoring the oligopeptides, whereas some small decreases in the photophysical parameters (𝜏F and ΦF), and larger decrease in T1 lifetimes are noted, which are attributable to the known "loose bolt" effect. The structure for 9 in solution was addressed qualitatively using computer modeling and the comparison of the bimolecular fluorescence quenching rate constants between 5 and 9 using C60 as a photooxidative agent. While 5 exhibits a totally accessible zinc(II)porphyrin unit for a C60 approach, 9 shows a slower quenching rate constant meaning some steric hindrance must be present.

The Rate constant of the Reaction of OH(A2Σ+) with H2O2(X˜1A)

2001 ◽  
Vol 215 (7) ◽  
Author(s):  
Walter Hack ◽  
R. Jordan
Keyword(s):  
Rate Constant ◽  
Room Temperature ◽  
Order Conditions ◽  
Oh Radicals ◽  
Quenching Rate ◽  
First Order ◽  
Electronically Excited State ◽  
Electronically Excited ◽  
Quenching Rate Constant ◽  
Pseudo First Order

The rate constant of the depletion of OH radicals in the first electronically excited state with hydrogenperoxid:OH(was determined at room temperature under pseudo first-order conditions [OH(The rate constant is:similar to the quenching rate constant of OH(

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