Hydrazines oxidation potentials

CdTe has been deposited by hydrazine reduction of TeOi [17,18]. The potential of hydrazine oxidation is sufficiently negative to allow formation of telluride ... 

The oxidation potentials in MeCN for several substituted hydrazines and amines are summarized in Table 11.1. 

In contrast, when hydroxide ion HO- is present, it is more easily oxidized than the amine substrates. In MeCN, in the absence of substrate, HO- is oxidized at +0.7-0.9 V versus SCE. However, with hydrazines and amines present, as in the case of H2NOH [Eq. (11.25)], the N—H bonds are homo-lytically cleaved by the HO product of HO- oxidation. The latter s oxidation potential is shifted by the difference in the HO—H and RN—H bond energies (—AGbf). Thus, the oxidation of PhNHNHPh is shifted by —1.7V when HO-becomes the electron-transfer mediator with PhNH2 the shift is —1.1 V ... 

TABLE 11.1 Oxidation Potentials for 1-5 mM Hydrazines and Amines in MeCN [0.1 M EtfNiClO ] and in the Presence of an Equivalent of HO- Evaluation of UN—H Bond Energies (—AGBF)... 

Nelsen and coworkers [562] detected conformational equilibria in eq, eq- and ax, eq-N, A -disubstituted cyclic hydrazines from their oxidation potentials. The anodic oxidation reactions of trans- and cw-l,3-diisopropy-l-2,4-bis(diisopropylamino)-cyclodiphospha(III)azanes are quite different [563] The trans isomer is reversibly oxidized at 0.53 V (SCE) forming a stable cation radical the c/5-isomer undergoes a completely irreversible oxidation at a more positive potential because an unstable radical cation is formed. Evans and coworkers studied structural changes associated with electron transfer reactions of W(// -C5(CH3)5)(CH3)4 and related compounds [564,565]. Yoshida and coworkers found a linear correlation on plotting the oxidation potentials of a-silylated ethers, where the rotation around the C-0 bond is restricted, against the HOMO energy-torsion angle (Si-C-O-C) curve estimated by MO calculation [566]. 

The preferred hydrazine oxidation at the anode far below the oxygen generation potential is the reason why Pu(III) is not or only in small amounts oxidized to Pu(IV) under these conditions. The complete conversion of Pu(III) to Pu(IV) is only possible after the hydrazine has been destroyed,... 

The recently reported correlation of reactivities, and one-electron oxidation potentials of nucleophiles is examined with new data for hydrazine in aqueous solution and several nucleophiles in (CH3)2SO solution. The correlation fails to apply to these reactions. A thermodynamic cycle is utilized to estimate the free energies of ionization of pyronin-nucleophile adducts both in solution and in the solid state. A satisfying rationalization of the dichotomy of ionic and covalent crystals of these and similar compounds is obtained. The equilibrium constants for reactions of nucleophiles with several types of cations are examined as indicators of specific bonding effects such as steric and gem interactions. 

Using the thermodynamic cycles presented earlier (3) with a value of 10.8 kcal/mol for the free energy of acid dissociation of hydrazinium ion in water, we obtain AG°5 = 16 kcal/mol for the standard oxidation potential of hydrazine in aqueous solution. 

ANHYDRONE (10034-81-8) A powerful oxidizer. Potentially violent or explosive reaction with reducing agents, alcohols, ammonia gas, argon (wet), butyl fluorides, dimethyl sulfoxide, ethylene oxide, fluorobutane (wet), fuels, hydrazines, hydrocarbons, mineral acids, powdered metals, organic matter, phosphorus, trimethyl phosphite. Mixture with ethanol forms explosive ethyl perchlorate. Incompatible with alkenes, and many other materials. Shock may cause magnesium perchlorate to explode. 

Many research efforts went into elucidating the behavior of different catalysts in the hydrazine oxidation reaction. Like the oxygen electrode, the open-circuit potential of a hydrazine electrode deviates from the thermodynamic value (—1.22 V) and in certain cases comes close to that of the hydrogen electrode... 

Potentials reported versus SCE have been corrected to versus Ag AgCl using +0.045 V conversion factor This paper presents the first evidence of hydrazine oxidation at neutral pH Microchip capillary electrophoresis/electrochemical detection of hydrazine... 

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