Analysis of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"><mml:mrow><mml:msub><mml:mrow><mml:mtext>S</mml:mtext></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:msubsup><mml:mrow><mml:mtext>Q</mml:mtext></mml:mrow><mml:mrow><mml:mtext>A</mml:mtext></mml:mrow><mml:mrow><mml:mo>-</mml:mo></mml:mrow></mml:msubsup></mml:mrow></mml:math> charge recombination with the Arrhenius, Eyring and Marcus theories

Rantamäki, Susanne; Tyystjärvi, Esa

doi:10.1016/j.jphotobiol.2011.03.013

Cited by 8 publications

(4 citation statements)

References 31 publications

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“…The low NaOH concentration tends to make the reaction less spontaneous. As for the kinetic parameters other reported works 7 , 8 , 13 also corroborate that the overall rate order of the hydrolysis of CV is 1st order. However, the previous works neither reported values of the individual rate order with respect to CV and NaOH nor did they report the detailed kinetic rate law for the hydrolysis reaction of CV, this information are the major novelty of this work.…”

Section: Resultssupporting

confidence: 80%

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Kinetics and thermodynamics of hydrolysis of crystal violet at ambient and below ambient temperatures

Salahudeen

Rasheed

2020

Sci Rep

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Hydrolysis reaction was carried out at varying NaOH concentrations of 0.008, 0.016 and 0.024 M, variable temperature of 6 and 21 °C, and constant initial crystal violet (CV) concentration of 2.6 × 10–5 M. Kinetic data of the reaction were generated using UV–Vis Spectrophotometer. Analysis of the reaction kinetics shows that the overall rate order of the hydrolysis reaction was 1st order. The individual rate order of the reaction with respect to NaOH and CV was temperature dependent. At 21 °C the rate order with respect to NaOH and CV were 0.24th and 0.76th, respectively. While at 6 °C the individual rate order were 0.38th and 0.62th with respect to NaOH and CV, respectively. Values of the reaction rate constant (k) at 21 and 6 °C were 7.2 and 1.9 $$\left( {\frac{{{\text{mol}}}}{{\text{L}}}} \right)^{{ - 0.9}} min^{-1}$$ mol L - 0.9 m i n - 1 , respectively. The activation energy of the reaction was determined as 60.57 kJ/mol. The reaction was an endothermic reaction having enthalpy values of 58.13 and 58.29 kJ/mol at 21 and 6 °C, respectively. The entropy and Gibbs free energy of the hydrolysis reaction at ambient temperature of 21 °C were − 64.72 J/mol K and 77.15 kJ/K, respectively. At 6 °C the entropy and Gibbs free energy of the reaction were − 64.29 J/mol K and 76.19 kJ/K, respectively.

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Section: Resultssupporting

confidence: 80%

“…Equation ( 22 ) is the Eyring equation 11 , 13 which relates the reaction rate constant, (k) with the enthalpy (∆H) and entropy (∆S) where is the Boltzman’s constant = 1.381 × 10 –23 J/K, h is the Planck’s constant = 6.626 × 10 –34 Js, T is the absolute temperature in Kelvin and R is the gas constant.…”

Section: Resultsmentioning

confidence: 99%

Kinetics and thermodynamics of hydrolysis of crystal violet at ambient and below ambient temperatures

Salahudeen

Rasheed

2020

Sci Rep

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“…2a). We applied the model of Rappaport & Lavergne (2009) for the analysis of the Q band (see also Rantamäki & Tyystjärvi, 2011). For the B band, a first‐order model with one recombining component (Randall & Wilkins, 1945; Tyystjärvi & Vass, 2004) was used.…”

Section: Resultsmentioning

confidence: 99%

Singlet oxygen production by photosystem II is caused by misses of the oxygen evolving complex

et al. 2022

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Singlet oxygen ( 1 O 2 ) is a harmful species that functions also as a signaling molecule. In chloroplasts, 1 O 2 is produced via charge recombination reactions in photosystem II, but which recombination pathway(s) produce triplet Chl and 1 O 2 remains open. Furthermore, the role of 1 O 2 in photoinhibition is not clear.We compared temperature dependences of 1 O 2 production, photoinhibition, and recombination pathways.1 O 2 production by pumpkin thylakoids increased from −2 to +35°C, ruling out recombination of the primary charge pair as a main contributor. S 2 Q A − or S 2 Q B − recombination pathways, in turn, had too steep temperature dependences. Instead, the temperature dependence of 1 O 2 production matched that of misses (failures of the oxygen (O 2 ) evolving complex to advance an S-state). Photoinhibition in vitro and in vivo (also in Synechocystis), and in the presence or absence of O 2 , had the same temperature dependence, but ultraviolet (UV)radiation-caused photoinhibition showed a weaker temperature response.We suggest that the miss-associated recombination of P 680 + Q A − is the main producer of 1 O 2 . Our results indicate three parallel photoinhibition mechanisms. The manganese mechanism dominates in UV radiation but also functions in white light. Mechanisms that depend on light absorption by Chls, having 1 O 2 or long-lived P 680 + as damaging agents, dominate in red light.

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“…As the temperature increased from 5.0 to 35.0 C, the rate of TCP degradation increased to 2.14-fold. Following some literature precedents [36][37][38][39][40][41], this dependence was interpreted by assuming that both k 1 and k 2 have Arrhenius type temperature dependencies with pre-exponential factors A 1 and A 2 and activation energies of E a1 and E a2 . The temperature dependence of the quantum yield is simply interpreted in this line of thought as follows:…”

Section: Kinetic Studiesmentioning

confidence: 99%

A detailed kinetic study of the direct photooxidation of 2,4,6-trichlorophenol

Pino-Chamorro

Ditrói

Lente

et al. 2016

Journal of Photochemistry and Photobiology A: Chemistry

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The direct photodegradation of 2,4,6-trichlorophenol (TCP) by UV-vis light was studied in aqueous solution in order to analyze the mechanism of the photochemical process and to determine the kinetic parameters including the quantum yield. Based on initial rate studies at different overall volumes and illumination patterns, it was proved that the rate of the process is directly proportional to the intensity of irradiating light. A significant, but moderate acceleration of the reaction rate with increasing temperature was revealed between 5.0 and 35.0 C, which could be interpreted readily by assuming that the excited state of TCP is involved in two competing processes. High pressure liquid chromatography and mass spectrometry provided us information on the nature of the intermediates and the products formed. 2,6-Dichloro-1,4-benzoquinone, 3,5-dichloro-2-hydroxy-1,4-benzoquinone and 2,6-dihclorohydroxyquinone were detected as products and/or intermediates, and there were also hints of the formation of 3,5-dichlorobenzene-1,2-diol and 3,5-dichloro-1,2-benzoquinone. A possible degradation mechanism is proposed to interpret the kinetic findings. 2016 Elsevier B.V. All rights reserved.

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Analysis of S2QA- charge recombination with the Arrhenius, Eyring and Marcus theories

Cited by 8 publications

References 31 publications

Kinetics and thermodynamics of hydrolysis of crystal violet at ambient and below ambient temperatures

Kinetics and thermodynamics of hydrolysis of crystal violet at ambient and below ambient temperatures

Singlet oxygen production by photosystem II is caused by misses of the oxygen evolving complex

A detailed kinetic study of the direct photooxidation of 2,4,6-trichlorophenol

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