scholarly journals Photochemistry of potassium ferrocyanide and its reaction with uridine 5'-monophosphate in an aqueous solution under ultraviolet irradiation

2021 ◽  
Keyword(s):  
Aqueous Solution ◽  
Ultraviolet Irradiation ◽  
Potassium Ferrocyanide

scholarly journals XV.—The Viscosity of Solutions

1907 ◽  
Vol 45 (2) ◽  
pp. 397-406 ◽  
Author(s):  
C. Ranken ◽  
W. W. Taylor
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Potassium Chloride ◽  
Mercuric Chloride ◽  
Potassium Ferricyanide ◽  
Potassium Ferrocyanide ◽  
Potassium Chlorate ◽  
Ammonium Iodide ◽  
Other Substances ◽  
Negative Viscosity

In a recent paper published by the authors, some measurements of the viscosity of aqueous solutions indicated that it would be of interest to investigate more fully the viscosity of solutions, especially those which exhibit what is now generally known as “negative viscosity,” over a wider range of temperature.This has now been done to a certain extent, and to enable a comparison to be made between electrolytes and non-electrolytes in aqueous solution, some other substances have been included in the investigation. They are:—potassium chloride, potassium chlorate, ammonium iodide, potassium ferricyanide, potassium ferrocyanide; mercuric chloride, mercuric cyanide; carbamide.

Photolysis of cyflufenamid in liquid media

2018 ◽  
Vol 78 (2) ◽  
pp. 424-431
Author(s):  
Zhangyu Zheng ◽  
Chunyan Zhang ◽  
Haiyan Shi ◽  
Zhiwei Liu ◽  
Jinsheng Duan ◽  
...  
Keyword(s):  
Adverse Effect ◽  
Aqueous Solution ◽  
Ultraviolet Irradiation ◽  
Ultrapure Water ◽  
Liquid Media ◽  
Initial Concentration ◽  
First Order ◽  
Positive Effects ◽  
First Order Kinetics ◽  
Factors Influencing

Abstract The photolysis of cyflufenamid (CFA) in different organic solvents and water under ultraviolet irradiation was investigated. The photolytic rate constant and photolytic half-life were measured for the different solutions. Factors influencing the photolysis of CFA were investigated, including initial concentration, types of solvent, pH, occurrence of catalyst (TiO2), and environmental substances (Fe3+, Fe2+, NO3−, NO2−). Photolysis of CFA followed first-order kinetics in various systems, and the photolytic rate of CFA decreased with increased initial concentration. Photolytic rates of CFA in different solvents were as follows: n-hexane > methanol > acetonitrile > ultrapure water > ethyl acetate. The pH had a significant effect on the photolysis of CFA, and the photolysis rate reached its peak at pH 9.0. NO2− and TiO2 had positive effects on the photolysis of CFA, while Fe2+ had an adverse effect. NO3− in aqueous solution had no effect on the photolysis of CFA. In addition, the rates of photolysis were accelerated at lower concentrations of Fe3+ (0.5–5 mmol L−1) and decreased at higher concentrations (10 mmol L−1). Moreover, a main photolytic product of CFA was confirmed to be N-cyclopropoxy-2,3-difluoro-6-(trifluoromethyl)benzamide, and cleavage of the amido bond was proposed to be the predicted photolysis pathway in n-hexane.

Regiospecificity and Stereoselectivity in the Photodimerization of 2,3-Dihydro-2,6-dimethyl-4-pyrone

1973 ◽  
Vol 51 (8) ◽  
pp. 1267-1277 ◽  
Author(s):  
Peter Yates ◽  
Donald J. MacGregor
Keyword(s):  
Aqueous Solution ◽  
Ultraviolet Irradiation ◽  
Spectroscopic Methods ◽  
Magnetic Spectrum ◽  
Nuclear Overhauser ◽  
Nuclear Overhauser Effects ◽  
Dimerization Reaction

Ultraviolet irradiation of 2,3-dihydro-2,6-dimethyl-4-pyrone in aqueous solution leads to the regiospecific and stereoselective formation of three cis–anti–cis photodimers of the cyclobutane type, i.e0., octahydro-2,7-8a,8b-tetramethylcyclobuta[1,2-b:4,3-b′]dipyran-4,5-diones, whose structures have been established by chemical and spectroscopic methods, including studies of nuclear Overhauser effects in the proton magnetic spectrum of one of them. The dimers undergo photointerconversion, and it is proposed that this process involves photoreversion to monomer and that the reversibility of the dimerization reaction may be a factor in determining the regiochemistry and stereochemistry of the photodimers. A bisdehydro product prepared from the dimers of the dihydropyrone has been shown to undergo photocleavage to 2,6-dimethyl-4-pyrone, and it is proposed that reversibility may also be a factor affecting the course of the photodimerization of this pyrone.

Photodegradation of Bis(4-Hydroxyphenyl) Methane Based on the Inclusion of Two Cyclodextrins under Ultraviolet Irradiation

2014 ◽  
Vol 665 ◽  
pp. 575-578
Author(s):  
Ji Ping Yu ◽  
Li Guo ◽  
An Yun Yang ◽  
Jian Xiang Li
Keyword(s):  
Aqueous Solution ◽  
Ultraviolet Irradiation ◽  
Inclusion Complexation ◽  
Reaction Model ◽  
Order Reaction ◽  
First Order ◽  
Photodegradation Efficiency ◽  
Cyclodextrin Inclusion ◽  
Inclusion Interaction ◽  
Kinetics Of

Photodegradation of bis (4-hydroxyphenyl) methane (BPE) was investigated under ultraviolet light (λ=254nm) based on the inclusion of two kinds cyclodextrin (α-CD, β-CD) in aqueous solution. The inclusion interaction of α-and β-cyclodextrin with BPE was characterized by fluorescence spectrophotometer. The addition of cyclodextrin could promote photodegradation efficiency of BPE, which the β-CD promoted the most. The kinetics of BPE photodegradation with different initial concentrations was investigated by first-order reaction model. Experiment results demonstrate that β-cyclodextrin inclusion complexation can accelerate BPE photodegradation in aqueous solution under ultraviolet irradiation.

Structures Formed by Cryoprotective Agents Used in Freezc-Etching

1971 ◽  
Vol 29 ◽  
pp. 448-449
Author(s):  
G. G. Cocks ◽  
C. E. Cluthe
Keyword(s):  
Aqueous Solution ◽  
Polyethylene Oxide ◽  
Liquid Nitrogen Temperature ◽  
Ice Crystals ◽  
Etching Technique ◽  
Structural Constituent ◽  
Cryoprotective Agents ◽  
Quick Freezing ◽  
Freeze Etching ◽  
Fractured Surface

The freeze etching technique is potentially useful for examining dilute solutions or suspensions of macromolecular materials. Quick freezing of aqueous solutions in Freon or propane at or near liquid nitrogen temperature produces relatively large ice crystals and these crystals may damage the structures to be examined. Cryoprotective agents may reduce damage to the specimem, hut their use often results in the formation of a different set of specimem artifacts.In a study of the structure of polyethylene oxide gels glycerol and sucrose were used as cryoprotective agents. The experiments reported here show some of the structures which can appear when these cryoprotective agents are used.Figure 1 shows a fractured surface of a frozen 25% aqueous solution of sucrose. The branches of dendritic ice crystals surrounded hy ice-sucrose eutectic can be seen. When this fractured surface is etched the ice in the dendrites sublimes giving the type of structure shown in Figure 2. The ice-sucrose eutectic etches much more slowly. It is the smooth continuous structural constituent surrounding the branches of the dendrites.

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