Systematic study of the explosive chemical kinetics of derivatives of ETN and PETN at low pressure

Kinetics of formation of 1,2,4-oxadiazoles from 24 substitution derivatives of O-benzoylbenzamidoxime have been studied in sulphuric acid and aqueous ethanol media. It has been found that this medium requires introduction of the Hammett H0 function instead of the pH scale beginning as low as from 0.1% solutions of mineral acids. Effects of the acid concentration, ionic strength, and temperature on the reaction rate and on the kinetic isotope effect have been followed. From these dependences and from polar effects of substituents it was concluded that along with the cyclization to 1,2,4-oxadiazoles there proceeds hydrolysis to benzamidoxime and benzoic acid. The reaction is thermodynamically controlled by the acid-base equilibrium of the O-benzylated benzamidoximes.

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Thermodynamics and kinetics of low pressure methanol synthesis

The Chemical Engineering Journal and the Biochemical Engineering Journal ◽

10.1016/0923-0467(94)02955-5 ◽

1995 ◽

Vol 58 (2) ◽

pp. 101-108 ◽

Cited By ~ 21

Author(s):

Jerzy Skrzypek ◽

Maria Lachowska ◽

Mirosław Grzesik ◽

Jerzy Słoczyński ◽

Paweł Nowak

Keyword(s):

Methanol Synthesis ◽

Low Pressure ◽

Thermodynamics And Kinetics ◽

Kinetics Of

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Influence of fluorophore and linker length on the localization and trafficking of fluorescent sterol probes

Scientific Reports ◽

10.1038/s41598-020-78085-9 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Jarmila Králová ◽

Michal Jurášek ◽

Lucie Mikšátková ◽

Anna Marešová ◽

Jan Fähnrich ◽

...

Keyword(s):

Genetic Mutation ◽

Cell Permeability ◽

Specific Cell ◽

Cell Compartments ◽

Intracellular Compartments ◽

Resolution Imaging ◽

Intracellular Labelling ◽

Kinetics Of Uptake ◽

Kinetics Of ◽

Derivatives Of

AbstractFluorescent sterol probes, comprising a fluorophore connected to a sterol backbone by means of a linker, are promising tools for enabling high-resolution imaging of intracellular cholesterol. In this study, we evaluated how the size of the linker, site of its attachment and nature of the fluorophore, affect the localization and trafficking properties of fluorescent sterol probes. Varying lengths of linker using the same fluorophore affected cell penetration and retention in specific cell compartments. A C-4 linker was confirmed as optimal. Derivatives of heterocyclic sterol precursors attached with identical C-4 linker to different fluorophores at diverse positions also showed significant differences in their binding properties to various intracellular compartments and kinetics of trafficking. Two novel red-emitting probes with good cell permeability, fast intracellular labelling and slightly different distribution displayed very promising characteristics for sterol probes. These probes also strongly labelled endo/lysosomal compartment in cells with pharmacologically disrupted cholesterol transport, or with a genetic mutation of cholesterol transporting protein NPC1, that overlapped with filipin staining of cholesterol. Overall, the present study demonstrates that the physicochemical properties of the fluorophore/linker pairing determine the kinetics of uptake and distribution and subsequently influence the applicability of final probes.

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CHEMICAL KINETICS OF WEATHERING IN YOUNG ANDISOLS FROM NORTHEASTERN JAPAN USING SOIL AGE NORMALIZED TO 10°C

Soil Science ◽

10.1097/00010694-199301000-00008 ◽

1993 ◽

Vol 155 (1) ◽

pp. 53-60 ◽

Cited By ~ 29

Author(s):

SADAO SHOJI ◽

MASAMI NANZYO ◽

YASUHITO SHIRATO ◽

TOYOAKI ITO

Keyword(s):

Chemical Kinetics ◽

Northeastern Japan ◽

Soil Age ◽

Kinetics Of

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Derivatives of isatin in aqueous solution. I. Kinetics of ring opening of Isatin-5-sulfonate

Australian Journal of Chemistry ◽

10.1071/ch9810365 ◽

1981 ◽

Vol 34 (2) ◽

pp. 365 ◽

Cited By ~ 7

Author(s):

H Stunzi

Keyword(s):

Ring Opening ◽

Rate Of Change ◽

Spectroscopic Methods ◽

Ph Values ◽

Buffer Region ◽

Pka Value ◽

Back Titration ◽

Kinetics Of ◽

Derivatives Of ◽

Sulfonate Anion

The reactions of isatin-5-sulfonate anion (si-) which cause a hysteresis in pH titrations were studied by pH-metric and n.m.r, spectroscopic methods. Rapid alkalimetric titrations [I 0.15 M (KNO3),37�] gave the pKa value corresponding to the addition of OH- to si- [pKa(ring) 9.55]. The slow ring opening to the sulfonatoisatate dianion (sia2-) led to a drift of the pH values towards an equilibrium buffer region. Its pKa, value [pKa(eq) 3.44] corresponds to the reaction si-+H2O ↔ sia 2-+H+ Rapid back-titration gave the pKa value of the ring-opened species Hsia- [pKa(open) c. 1.3]. The rate law for the ring opening d[sia]/dt=k2 [siOH](OH)+k1*[si] was obtained from the rate of change of pH. N-Methylisatin-5-sulfonate behaves analogously.

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Vulcanization of Elastomers. 23. The Chemical Kinetics of Vulcanization Reactions and The Physical Properties of The Vulcanizates. I

Rubber Chemistry and Technology ◽

10.5254/1.3542149 ◽

1960 ◽

Vol 33 (2) ◽

pp. 335-341

Author(s):

Walter Scheele ◽

Karl-Heinz Hillmer

Keyword(s):

Activation Energy ◽

Physical Properties ◽

Chemical Kinetics ◽

Kcal Mole ◽

First Order ◽

Equilibrium Swelling ◽

Kinetics Of ◽

Kinetics Of Vulcanization ◽

Limiting Value ◽

Good Agreement

Abstract As a complement to earlier investigations, and in order to examine more closely the connection between the chemical kinetics and the changes with vulcanization time of the physical properties in the case of vulcanization reactions, we used thiuram vulcanizations as an example, and concerned ourselves with the dependence of stress values (moduli) at different degrees of elongation and different vulcanization temperatures. We found: 1. Stress values attain a limiting value, dependent on the degree of elongation, but independent of the vulcanization temperature at constant elongation. 2. The rise in stress values with the vulcanization time is characterized by an initial delay, which, however, is practically nonexistent at higher temperatures. 3. The kinetics of the increase in stress values with vulcanization time are both qualitatively and quantitatively in accord with the dependence of the reciprocal equilibrium swelling on the vulcanization time; both processes, after a retardation, go according to the first order law and at the same rate. 4. From the temperature dependence of the rate constants of reciprocal equilibrium swelling, as well as of the increase in stress, an activation energy of 22 kcal/mole can be calculated, in good agreement with the activation energy of dithiocarbamate formation in thiuram vulcanizations.

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