Oxidation-Reduction Reactions of Metal Ions

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Upon coordination to metal ions, C-alkylpyrogallol[4]arenes (PgCn, where n is the number of carbon atoms in the pendant alkyl chains), can be assembled into spherical metal-organic nanocapsules (MONCs). MONCs are generally arranged into two different structural types, hexamers and dimers, of which six or two PgCn units assemble into capsular structures by coordination to 24 or 8 metal ions, respectively. Co[II]-, Zn[II]-, and Mn[II]-coordinated MONCs have been synthesized under ambient conditions and structurally characterized. Under certain reaction conditions, some transition metal ions and other reagents seem to act as electron accepting or donating reagents, such that appropriate oxidation or reduction reactions may occur. These types of in-situ redox reactions lead to the formation of mixed-valence Mn[II]/Mn[III]- and Fe[II]/Fe[III]-seamed MONCs. The occurrence of such oxidation/reduction reactions appears to be promoted by certain factors such as resulting pH conditions, size of the coordinating ions/ligands, and oxidizing/reducing abilities of reagents used in each synthesis. In addition, studies have been carried out to incorporate some defects into the MONC outer framework by using mixed-macrocycles as the starting materials. Mixed-macrocycles are synthesized by fusing both resorcinol and pyrogallol into the same macrocycle, and the position of resorcinol units in the MONC usually appears as a hole or defect on the capsule surface. Incorporations of such defects give MONCs potential for, for example, selective filtering of small molecules into the capsule interior and magnetic and electronic applications by varying the electrostatic interaction between adjacent metal ions.

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Slippery Liquid-Immobilized Coating Films Using in Situ Oxidation–Reduction Reactions of Metal Ions in Polyelectrolyte Films

ACS Applied Materials & Interfaces ◽

10.1021/acsami.7b01869 ◽

2017 ◽

Vol 9 (17) ◽

pp. 15122-15129 ◽

Cited By ~ 13

Author(s):

Yosuke Tsuge ◽

Takeo Moriya ◽

Yukari Moriyama ◽

Yuki Tokura ◽

Seimei Shiratori

Keyword(s):

Metal Ions ◽

Coating Films ◽

In Situ Oxidation ◽

Reduction Reactions ◽

Oxidation Reduction

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Oxidation-reduction reactions of metal ions.

Environmental Health Perspectives ◽

10.1289/ehp.95103s117 ◽

1995 ◽

Vol 103 (suppl 1) ◽

pp. 17-19 ◽

Cited By ~ 24

Author(s):

D E Carter

Keyword(s):

Metal Ions ◽

Reduction Reactions ◽

Oxidation Reduction

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THE PRINCIPLE OF EQUIVALENCE CHANGE IN OXIDATION–REDUCTION REACTIONS

Canadian Journal of Chemistry ◽

10.1139/v59-021 ◽

1959 ◽

Vol 37 (1) ◽

pp. 148-154 ◽

Cited By ~ 13

Author(s):

J. Halpern

Keyword(s):

Electron Transfer ◽

Metal Ions ◽

Activation Energies ◽

Principle Of Equivalence ◽

Reduction Reactions ◽

Chain Reactions ◽

Oxidation Reduction ◽

Lower Activation ◽

Equivalence Type ◽

Mechanisms Of Reactions

The principle of equivalence change predicts that oxidation–reduction reactions between 1-equivalent oxidants and 2-equivalent reductants (or vice versa) will, in general, be slow, since they must proceed either through termolecular paths or through the formation of unstable intermediates. In this paper, the kinetics and mechanisms of a number of reactions of this type are examined and an attempt is made to assess the validity of the considerations on which this principle is based. Among the reactions considered are (1) electron transfer between metal ions; (2) oxidation of metal ions by oxygen; and (3) reduction of metal ions by hydrogen. In each of these cases it is found that the principle of equivalence change has only limited validity and that a number of other factors are important in determining the relative rates and mechanisms of reactions of different equivalence type. Among these are the formation of stabilized intermediate complexes between oxidant and reductant and the possibility of unstable intermediates acting as carriers in chain reactions. In reactions of thallium(I) or thallium(III) with 1-equivalent metal ions, thallium(II) is formed as an intermediate. Some of these reactions are not as slow as expected, apparently because of favorable entropies of activation. Several of the reactions examined proceed simultaneously through bimolecular and termolecular paths, the latter being favored because of lower activation energies.

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Feedback Controlled Chemical Reactor with Feed of Two Reaction Components with Spectrophotometric Indication

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19940549 ◽

1994 ◽

Vol 59 (3) ◽

pp. 549-557

Author(s):

František Skopal ◽

Václav Dušek

Keyword(s):

Sulfuric Acid ◽

Negative Feedback ◽

Chemical Reactor ◽

Reduction Reactions ◽

Oxidation Reduction

Theoretical relationships and simplifying conditions have been derived for the feed of two reaction components into a nonisochoric reactor with ideal stirring. The feed of reaction components is controlled by the negative feedback at a constant absorbance of the reaction mixture. The theoretical relationships have been verified using model 2. order oxidation-reduction reactions of Ce(IV)/V(IV) and Fe(III)/V(III) in 1 M sulfuric acid at 20 °C.

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