Kinetic, Thermodynamic Studies for Photo Degradation of Glibinclamide Drug

Author(s):  
Amel S. Mahdi ◽  
Barakat A. F. Kamel ◽  
Athraa S. Ahmed ◽  
Kafi M. Dawood

In this work the photo degradation of glibinclamide is studied by UV light and different concentrations using solvents (water and ethanol) and different times. The reaction kinetic is studied and found that the photo degradation reaction of glibinclamide is (first-order) reaction and the thermodynamic properties (ΔHo, ΔSo and ΔGo) for glibinclamide were calculated and it was found to be (endothermic and spontaneous reaction).

2014 ◽  
Vol 1078 ◽  
pp. 98-101
Author(s):  
Guan Ming Liao ◽  
Chun Hong Zheng ◽  
Shou Zhi Pu

An asymmetrical photochromic diarylethene1-(2-Methyl-3-benzothiophene)-2-[2-methyl-5-(3-fluoro-4-chloro) phenyl-3-thienyl] perfluorocyclopentene (1o) was synthesized and its phtochromic, fluorescent properties were investigated in detail. This compound exhibited remarkable photochromism, upon irradiation with 297 nm UV light, the colorless solution of 1o turned to violetred with a new visible absorption band centered at 538 nm (ε = 1.17 × 104 L mol-1 cm-1) attributable to the closed-ring isomer 1c. The kinetic experiments showed that the cyclization and cycloreversion processes were zeroth and first order reaction, respectively. Moreover, diarylethene 1o also exhibited obviously fluorescence switches along with the photochromism.The emission intensity of diarylethene 1o in a photostationary state was quenched to ca. 27% in hexane.


2013 ◽  
Vol 830 ◽  
pp. 278-281
Author(s):  
Zhi Yuan Sun ◽  
Wei Wei Geng ◽  
Shou Zhi Pu

A new photochromic diarylethene compound 1-(2-cyan-3-phenyl)-2-[5-(4-cyanobenzene) -2-methyl-3-thienyl] perfluorocyclopentene was synthesized. And their properties inculding photochromis, fluorescence in both hexane and solid films, reaction kinetics of cyclization and cycloreversion were studied. And its absorption maxima were observed at 539 nm in hexane and at 552 nm in PMMA films, respectively, upon irradiation with 313 nm UV light. The fluorescence intensity of diarylethene decreased upon irradiation with 313 nm UV light. Besides, the cyclization and cycloreversion processes of the compound were determined to be the zeroth and first order reaction by UV-Vis spectra, respectively.


2013 ◽  
Vol 327 ◽  
pp. 78-82
Author(s):  
Zhi Yuan Sun ◽  
Xiao Dan Zhang ◽  
Shi Qiang Cui ◽  
Shou Zhi Pu

A novel unsymmetrical photochromic diarylethene 1-(2-methyl-3-benzofuran)-2-[5-(2-methylbenzene)-2-methyl-3-thieny perfluorocyclopentene1owas synthesized, then its photochromic, Kinetics and fluorescence properties were investigated. The results showed that the diarylethene compound had good photochromism upon irradiation with 297 nm UV light, in which the absorption maximum were observed at 510 nm in hexane solution and 524 nm in poly methyl methacrylate (PMMA) film. Besides, the cyclization and cycloreversion process of the compound were determined to be the zeroth and first order reaction by UV-Vis spectra, respectively. And, the open-ring isomer of the diarylethene exhibited relatively stronger fluorescence at 427 nm when excited at 273 nm in hexane solution.


2013 ◽  
Vol 473 ◽  
pp. 77-80
Author(s):  
Zhi Yuan Sun ◽  
Dan Dan Xue ◽  
Shou Zhi Pu

An unsymmetrical photochromic diarylethene 1-(2-trifluoromethylphenyl)-2-[2-methyl-5-(3-N,N-dimethylphenyl)-3-thienyperfluorocyclopentene (1a) was synthesized and its photochromism, fluorescent properties and reaction kinetics of cyclization and cycloreversion were studied in detail. The compound exhibited remarkable photochromism and its absorption maxima were observed at 552 nm in hexane and at 569 nm in PMMA films upon irradiation with 297 nm UV light. The fluorescence intensity of diarylethene decreased upon irradiation with 297 nm UV light. In addiation, reaction kinetics of the cyclization and cycloreversion processes of the compound were determined to be the zeroth and first order reaction by UV-Vis spectra, respectively.


2014 ◽  
Vol 952 ◽  
pp. 79-83
Author(s):  
Feng Xia Sun ◽  
Shi Qiang Cui ◽  
Shou Zhi Pu

A new unsymmetrical photochromic diarylethene compound, 1-(2-Methyl-3-benzothiophene)-2-(5-(4-ethynyl)-2-methylthiophen-3-yl)Perfluorocyclopentene (1o),was synthesized and its photochemical, fluorescence properties were investigated systematically both in solution and PMMA amorphous film. The results showed that this compound exhibited reversible photochromism, changing from colorless to pink after irradiation with 297 nm UV light both in solution and in PMMA amorphous film. The photochromic reaction kinetics indicated that the cyclization processes of 1 belong to the zeroth order reaction and the cycloreversion process belong to the first order reaction.


1991 ◽  
Vol 23 (1-3) ◽  
pp. 377-387 ◽  
Author(s):  
J. M. Tseng ◽  
C. P. Huang

Photocatalyst, TiO2, upon irradiation with uv light produces electrons and positive holes. The positive holes are strong oxidation agents that can oxidize organic compounds such as chlorophenol to mineral acids e.g. HC1 and CO2. Factors such as pH, chlorophenol concentration, concentration of TiO2 and inorganic electrolytes that may affect the oxidation of chlorophenol were investigated. The rate of the chlorophenol oxidation follows a first order reaction with respect to the chlorophenol concentration and independent of pH. The rate increases with concentration of TiO2, reaches a maximum level at 3 g/L then decreases to a constant value upon further increase in TiO2. Increasing the degree of chlorination appears to increase the extent and the rate of oxidation. For mono-chlorophenols the extent of oxidation follows: 4-chloro > 3-chloro > 2-chloro phenol. For dichlorophenols, the order is 2,6-dichloro ≈ 2,5-dichloro > 2,4-dichloro≈ 2,3-dichlorophenol. For symmetrical chlorophenols, the oxidation increases in the order: 4-chloro > 2,5-dichloro > 2,4,6-trichlorophenol. Pentachlorophenol is rapidly decomposed but the extent of oxidation is not complete.


2014 ◽  
Vol 1003 ◽  
pp. 27-30
Author(s):  
Guan Ming Liao ◽  
Dan Dan Xue ◽  
Chun Hong Zheng ◽  
Shou Zhi Pu

An asymmetrical photochromic diarylethene 1-(3,5-Dimethyl-4-isoxazolyl)-2-[2-methyl-5-(p-ethoxyphenyl)-3-thienyl] perfluorocyclopentene (1o) was synthesized and its photochromic properties were investigated. Upon irradiation with 297 nm UV light, 1o exhibited photochromism in hexane solution. The kinetic experiments showed that the cyclization and cycloreversion processes were zeroth and first order reaction, respectively. Moreover, diarylethene 1o also exhibited obviously fluorescence switches along with the photochromism.


2018 ◽  
Vol 16 (3) ◽  
pp. 347
Author(s):  
Candra Purnawan ◽  
Sayekti Wahyuningsih ◽  
Pramudita Putri Kusuma

Synthesis of graphite/PbTiO3 composite as a catalyst in photodegradation and photoelectrodegradation process of methyl orange have been conducted. The purposes of this research are to study the effect of radiation time, composition of composite, voltage and pH of solution for methyl orange degradation. Photodegradation process of methyl orange was carried out for 5; 10; 15; 20; 25 and 30 min. Ratio of graphite : PbTiO3 (w/w) were varied at 1:3; 1:2; 1:1; 2:1 and 3:1. Meanwhile, the applied voltages were 7.5; 10 and 12.5 V and the photoelectrodegradation was conducted under pH condition of 3; 7; and 11, respectively. The result showed that optimum composition of graphite/PbTiO3 in the methyl orange photodegradation was obtained at 1:1 ratio for 30 min with degradation up to 90.43% ± 0.062. The degradation reaction follows first order reaction with a rate constant of 0.0688 min-1. The optimum voltage is 10 V, in which it reduced the methyl orange concentration up to 92.65% ± 0 with a rate constant 0.0941 min-1 for first order reaction. The optimum pH is pH = 11, that provide methyl orange reduction up to 95.28% ± 0.082.


2014 ◽  
Vol 886 ◽  
pp. 143-146
Author(s):  
Xiao Rong Dong ◽  
Sha Sha Wei ◽  
Gang Liu ◽  
Shou Zhi Pu

A new unsymmetrical photochromic diarylethene compound, 1-(2-methyl-3-benzothiophene)-2-[2-methyl-5-(4-aminomethanephenyl)-3-thienyperfluorocyclopentene (1a) was synthesized, its photochromic properties were examined, the result indicated that the Diarylethene 1a changed the color from colorless to purple upon irradiation with 297 nm UV light, in which absorption maxima were observed at 564 in acetonitrile. The photochromic reaction kinetics indicated that the cyclization processes of 1a belong to the zeroth order reaction and the cycloreversion process belong to the first order reaction. This new photochromic system also exhibited fluorescence switching in acetonitrile solution.


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