Reactivity of Hydrogen Atoms toward Some Cobalt (III) Complexes in Aqueous Solutions

Jack Halpern; Joseph Rabani

doi:10.1021/ja00956a015

Reactivity of Hydrogen Atoms toward Some Cobalt (III) Complexes in Aqueous Solutions

Jack Halpern
, Joseph Rabani

Research output: Contribution to journal › Article › peer-review

25 Scopus citations

Abstract

Kinetic studies on the reduction of various cobalt(III) complexes by hydrogen atoms are described. The hydrogen atoms were generated by Co⁶⁰ γ irradiation of the solutions and the rates of reaction with thecobalt(III) complexes determined by competition with the reaction with ethanol. Rate constants ranging from 3.3 X 10¹⁰ to 2.0 X 10⁷ M^-1 sec^-1 (at 26°) were determined for the reactions of H atoms with Co(NH₃)₅I²⁺, Co(NH₃)₅Br²+, Co-(NH₃)₅NCS²+, Co(NH₃)₅(H-fumarate)²⁺, Co(NH₃)₅Cl²⁺, Co(NH₃)₅N₃²⁺, Co(NH₃)₃(N0₂)₃, Co(NH₃)₅N0₂²+, Co-(NH₃)₅CN²+, and Co(CN)₆^3-, along with upper limits for reactions with a number of other cobalt(III) complexes. In a number of cases the rates of reactions with the corresponding free ligands also were determined. The mechanisms of these reactions and the relation of the observed reactivity patterns for H atoms to those for other reductants are considered.

Original language	English
Pages (from-to)	699-704
Number of pages	6
Journal	Journal of the American Chemical Society
Volume	88
Issue number	4
DOIs	https://doi.org/10.1021/ja00956a015
State	Published - Feb 1966
Externally published	Yes

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@article{ba44828a3fe4482a929dda60e6bbbf8f,

title = "Reactivity of Hydrogen Atoms toward Some Cobalt (III) Complexes in Aqueous Solutions",

abstract = "Kinetic studies on the reduction of various cobalt(III) complexes by hydrogen atoms are described. The hydrogen atoms were generated by Co60 γ irradiation of the solutions and the rates of reaction with thecobalt(III) complexes determined by competition with the reaction with ethanol. Rate constants ranging from 3.3 X 1010 to 2.0 X 107 M-1 sec-1 (at 26°) were determined for the reactions of H atoms with Co(NH3)5I2+, Co(NH3)5Br2+, Co-(NH3)5NCS2+, Co(NH3)5(H-fumarate)2+, Co(NH3)5Cl2+, Co(NH3)5N32+, Co(NH3)3(N02)3, Co(NH3)5N022+, Co-(NH3)5CN2+, and Co(CN)63-, along with upper limits for reactions with a number of other cobalt(III) complexes. In a number of cases the rates of reactions with the corresponding free ligands also were determined. The mechanisms of these reactions and the relation of the observed reactivity patterns for H atoms to those for other reductants are considered.",

author = "Jack Halpern and Joseph Rabani",

year = "1966",

month = feb,

doi = "10.1021/ja00956a015",

language = "אנגלית",

volume = "88",

pages = "699--704",

journal = "Journal of the American Chemical Society",

issn = "0002-7863",

publisher = "American Chemical Society",

number = "4",

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TY - JOUR

T1 - Reactivity of Hydrogen Atoms toward Some Cobalt (III) Complexes in Aqueous Solutions

AU - Halpern, Jack

AU - Rabani, Joseph

PY - 1966/2

Y1 - 1966/2

N2 - Kinetic studies on the reduction of various cobalt(III) complexes by hydrogen atoms are described. The hydrogen atoms were generated by Co60 γ irradiation of the solutions and the rates of reaction with thecobalt(III) complexes determined by competition with the reaction with ethanol. Rate constants ranging from 3.3 X 1010 to 2.0 X 107 M-1 sec-1 (at 26°) were determined for the reactions of H atoms with Co(NH3)5I2+, Co(NH3)5Br2+, Co-(NH3)5NCS2+, Co(NH3)5(H-fumarate)2+, Co(NH3)5Cl2+, Co(NH3)5N32+, Co(NH3)3(N02)3, Co(NH3)5N022+, Co-(NH3)5CN2+, and Co(CN)63-, along with upper limits for reactions with a number of other cobalt(III) complexes. In a number of cases the rates of reactions with the corresponding free ligands also were determined. The mechanisms of these reactions and the relation of the observed reactivity patterns for H atoms to those for other reductants are considered.

AB - Kinetic studies on the reduction of various cobalt(III) complexes by hydrogen atoms are described. The hydrogen atoms were generated by Co60 γ irradiation of the solutions and the rates of reaction with thecobalt(III) complexes determined by competition with the reaction with ethanol. Rate constants ranging from 3.3 X 1010 to 2.0 X 107 M-1 sec-1 (at 26°) were determined for the reactions of H atoms with Co(NH3)5I2+, Co(NH3)5Br2+, Co-(NH3)5NCS2+, Co(NH3)5(H-fumarate)2+, Co(NH3)5Cl2+, Co(NH3)5N32+, Co(NH3)3(N02)3, Co(NH3)5N022+, Co-(NH3)5CN2+, and Co(CN)63-, along with upper limits for reactions with a number of other cobalt(III) complexes. In a number of cases the rates of reactions with the corresponding free ligands also were determined. The mechanisms of these reactions and the relation of the observed reactivity patterns for H atoms to those for other reductants are considered.

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DO - 10.1021/ja00956a015

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AN - SCOPUS:15544379008

SN - 0002-7863

VL - 88

SP - 699

EP - 704

JO - Journal of the American Chemical Society

JF - Journal of the American Chemical Society

IS - 4

ER -

Reactivity of Hydrogen Atoms toward Some Cobalt (III) Complexes in Aqueous Solutions

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