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Please use this identifier to cite or link to this item: http://repository.iitr.ac.in/handle/123456789/11424
Title: Electrochemistry and Spectroelectrochemistry of Cobalt Porphyrins with π-Extending and/or Highly Electron-Withdrawing Pyrrole Substituents. in Situ Electrogeneration of σ-Bonded Complexes
Authors: Ke X.
Kumar R.
Sankar, Muniappan
Kadish K.M.
Published in: Inorganic Chemistry
Abstract: A series of cobalt porphyrins with Ï€-extending or highly electron-withdrawing β-pyrrole substituents were investigated as to their electrochemistry, spectroscopic properties, and reactivity after electroreduction or electroxidation in nonaqueous media. Each porphyrin, represented as PorCo (where Por = TPP(NO2)Y2 or TPP(NO2)Y6 and Y = phenyl, phenylethynyl, Br, or CN) was shown to undergo multiple redox reactions involving the conjugated Ï€-ring system or central metal ion which could exist in a Co(III), Co(II), or Co(I) oxidation state under the application of an applied oxidizing or reducing potential. Thermodynamic half-wave potentials for the stepwise conversion between each oxidation state of [PorCo]n (where n ranged from +3 to -3) were measured by cyclic voltammetry and analyzed as a function of the compound structure and properties of the electrochemical solvent. UV-visible spectra were obtained for each oxidized or reduced porphyrin in up to six different oxidation states ranging from [PorCo]3- to [PorCo]3+ and analyzed as a function of the compound structure and utilized electrochemical solvent. Chemically or electrochemically generated Co(I) porphyrins are known to be highly reactive in solutions containing alkyl or aryl halides, and this property was utilized to in situ generate a new series of methyl carbon-bonded cobalt(III) porphyrins with the same Ï€-extending or highly electron-withdrawing substituents as the initial Co(II) derivatives. The electrosynthesized carbon-bonded Co(III) porphyrins were then characterized as to their own electrochemical and spectroscopic properties after the addition of one, two, or three electrons in nonaqueous media. © 2018 American Chemical Society.
Citation: Inorganic Chemistry (2018), 57(3): 1490-1503
URI: https://doi.org/10.1021/acs.inorgchem.7b02856
http://repository.iitr.ac.in/handle/123456789/11424
Issue Date: 2018
Publisher: American Chemical Society
ISSN: 201669
Author Scopus IDs: 57193522535
55389796000
6701530390
7004463259
Author Affiliations: Ke, X., Department of Chemistry, University of Houston, Houston, TX 77204-5003, United States
Kumar, R., Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee, 247667, India
Sankar, M., Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee, 247667, India
Kadish, K.M., Department of Chemistry, University of Houston, Houston, TX 77204-5003, United States
Funding Details: The support of the Robert A. Welch Foundation (KMK, Grant E-680) is gratefully acknowledged. M.S. sincerely thanks the Science and Engineering Research Board (EMR/2016/4016) for financial support. R.K. thanks the Ministry of Human Resource Development, India, for a Senior Research Fellowship
Corresponding Author: Sankar, M.; Department of Chemistry, Indian Institute of Technology RoorkeeIndia; email: sankafcy@iitr.ac.in
Appears in Collections:Journal Publications [CY]
Journal Publications [ME]

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