Potentiometric Studies on the Complexation Reactions ofN-(2,2-[1-(3-Aminophenyl)ethylidene]hydrazino-2-oxoethyl)benzamide with Ni2+, Cu2+, and Cd2+Ions in Aqueous Dioxane and Micellar Media

Disodium 1,5- and 1,8-anthracenedisulphonate (ADS) and 9-acetylanthracene form coloured CT complexes with methylviologen (MV2+) in aqueous and micellar media. The complex formation constants and molar absorptivities were determined by the Benesi-Hildebrandt method. In the fluorescence quenching, its static component plays the major role. The dynamic quenching component is determined by the rate constant of electron transfer from the S1 state of ADS to MV2+.

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ChemInform Abstract: COMPLEXES OF TIN(II). PART XII. POTENTIOMETRIC STUDIES ON FORMATION OF COMPLEXES IN THE SYSTEMS- TIN(II)-L-WATER (L = 2-PROPENOATE, 2-CHLOROPROPIONATE, 3-CHLOROPROPIONATE, 2-BROMOPROPIONATE, 3-BROMOPROPIONATE AND BROMOACETATE)

Chemischer Informationsdienst ◽

10.1002/chin.197637066 ◽

1976 ◽

Vol 7 (37) ◽

pp. no-no

Author(s):

RYSZARD WOJTAS

Keyword(s):

Potentiometric Studies ◽

Formation Of Complexes

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Kinetics and Mechanism of the Change of the 4-Nitrobenzylthio-System into 4,4′-Diformylazoxybenzene in Alkaline Dioxane-Water Media

Zeitschrift für Naturforschung A ◽

10.1515/zna-1985-1109 ◽

1985 ◽

Vol 40 (11) ◽

pp. 1128-1132

Author(s):

Y. Riad ◽

Adel N. Asaad ◽

G.-A. S. Gohar ◽

A. A. Abdallah

Keyword(s):

Acetic Acid ◽

Sodium Hydroxide ◽

Rate Constants ◽

Main Product ◽

Reaction Medium ◽

Aqueous Dioxane ◽

Proton Abstraction ◽

First Order ◽

Water Media ◽

Different Temperatures

Sodium hydroxide reacts with α -(4-nitrobenzylthio)-acetic acid in aqueous-dioxane media to give 4,4'-diformylazoxybenzene as the main product besides 4,4'-dicarboxyazoxybenzene and a nitrone acid. This reaction was kinetically studied in presence of excess of alkali in different dioxane-water media at different temperatures. It started by a fast reversible a-proton abstraction step followed by two consecutive irreversible first-order steps forming two intermediates (α -hydroxy, 4-nitrosobenzylthio)-acetic acid and 4-nitrosobenzaldehyde. The latter underwent a Cannizzaro's reaction, the products of which changed in the reaction medium into 4,4'-diformylazoxybenzene and 4,4'-dicarboxyazoxybenzene. The rate constants and the thermodynamic parameters of the two consecutive steps were calculated and discussed. A mechanism was put forward for the formation of the nitrone acid.Other six 4-nitrobenzyl, aryl sulphides were qualitatively studied and they gave mainly 4,4'-diformylazoxybenzene beside 4,4'-dicarboxyazoxybenzene or its corresponding azo acid.

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THE ALKALINE CLEAVAGE OF o-NITROBENZYLTRIMETHYLSILANE SOLVENT EFFECTS IN THE DIOXANE–WATER SYSTEM

Canadian Journal of Chemistry ◽

10.1139/v63-207 ◽

1963 ◽

Vol 41 (6) ◽

pp. 1525-1530 ◽

Cited By ~ 2

Author(s):

H. R. Allcock

Keyword(s):

Transition State ◽

Solvent Effects ◽

Water System ◽

Solvent Polarity ◽

High Water ◽

Aqueous Dioxane ◽

Alkaline Cleavage ◽

Rate Of Reaction ◽

Kinetics Of

The kinetics of alkaline cleavage of o-nitrobenzyltrimethylsilane were examined in aqueous dioxane media. At high water concentrations, increases in solvent polarity retard the cleavage, as required by a mechanism involving charge dispersion in the transition state. At high dioxane concentrations, solvent polarity increases are accompanied by increases in the rate of reaction, a result which may reflect association between the solvent components.

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