Studies in polarographic analysis

Issa, I. M.; Issa, R. M.; Hewaidy, I.F.; Omar, Emad

doi:10.1016/s0003-2670(00)87062-2

Cited by 15 publications

(6 citation statements)

References 5 publications

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“…Triethanolamine forms stable complexes in alkaline solution with divalent and trivalent metal ions such as Mn + ++, i~-n ++, Fe +++, and Fe + + (8,9). Discharges at a constant current of 3 ma were carried out in 1.0 and 9M KOH solutions containing 10-20% triethanolamine by volume.…”

Section: Effect Of Friethanolarnine Added To the Electrolyte--mentioning

confidence: 99%

The Cathodic Reduction Mechanism of Electrolytic Manganese Dioxide in Alkaline Electrolyte

Kozawa¹,

Yeager²

1965

J. Electrochem. Soc.

190

134

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Constant‐current discharge curves for electrodeposited MnO2 on graphite showed a two‐stage reduction; MnO2.0 to MnO1.5 and MnO1.5 to MnO1.0 . Potential decreased continuously during the first stage and in some discharges was constant for at least half of the second. The first stage was not influenced by current density, KOH concentration, MnO2 thickness, or a complexing agent. The constant‐potential portion was observed with 9MKOH , low current density; the potential was near the standard redox potential of Mn(II) and Mn(III) species in solution as determined polarographically. The first stage is considered a homogeneous phase reduction, while the second stage involves a heterogeneous system. A new mechanism is suggested for the latter.

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Section: Effect Of Friethanolarnine Added To the Electrolyte--mentioning

confidence: 99%

The Cathodic Reduction Mechanism of Electrolytic Manganese Dioxide in Alkaline Electrolyte

Kozawa¹,

Yeager²

1965

J. Electrochem. Soc.

190

134

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“…Although the carbonyl dinitrogen systems of chromium, molybdenum, and tungsten are evidently closely related in the spectral patterns and photochemistry which they exhibit, the 0020-1669/78/1317-0523501.00/0 present account is concerned preeminently with the molybdenum system for which there is maximum common ground between the infrared and Raman measurements carried out for the most part independently in our two laboratories.10 The formation and trapping in matrices of other mixed carbonyl dinitrogen derivatives of molybdenum, which have been characterized only by their infrared spectra, will be treated separately in a future paper;11 elsewhere too will be found a more detailed account of the experiments exploring the suitability of the Raman effect for monitoring photochemical changes of matrix-isolated metal carbonyls. 12 To the best of our knowledge, the only allusion hitherto made to a mixed carbonyl dinitrogen derivative of the group 6 elements concerns the chromium compound Cr(CO)5N2…”

Section: Introductionmentioning

confidence: 99%

Polarographic and spectroscopic studies of the manganese(II), -(III), and -(IV) complexes formed by polyhydroxy ligands

Magers¹,

Smith²,

Sawyer³

1978

Inorg. Chem.

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The complexes of manganese with aliphatic and aromatic polyhydroxy ligands in basic media have been studied by electrochemical, spectrophotometric, and magnetic methods. The results indicate that glucarate, glycerate, L-tartrate, and meso-tartrate stabilize the +2, +3, and +4 oxidation states of manganese in much the same manner as gluconate ion. Sorbitol, mannitol, inositol, nzeso-erythritol, glycerol, 2,3-butanediol, and ethylene glycol do not appreciably form soluble Mn(II) complexes but produce stable Mn(III) and Mn(IV) complexes. Diethanolamine, triethanolamine, tartronate, and glycolate also form stable Mn(II) and -(III) complexes as well as transiently stable Mn(IV) complexes. Catechol,2, l,2-dihydroxybenzene-3,5-disulfonate (Tirón), 3,5-di-íert-butylcatechol (DTBC), tetrafluorocatechol, 4,5-dihydroxynaphthalene-2,7-disulfonate, and salicylate stabilize the +2 and +3 oxidation states of manganese. A tris(DTBC semiquinone)manganese(III) complex is produced by oxidation of the Mn(II)-DTBC complex. The redox chemistry and solution equilibria for this group of complexes have been evaluated.

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“…The dead-stop titration method for oxidation of Mn+! to Mn+3 in pyrophosphate solution was studied by a number of workers (123,218,239) for determination of manganese in iron and steel as was the polarographic method (118,225). Variables that affect the spectrographic determination of manganese were evaluated (159).…”

Section: Manganesementioning

confidence: 99%