Factors determining the site of electroreduction in nickel metalloporphyrins. Spectral characterization of Ni(I) porphyrins, Ni(II) porphyrin. pi. -anion radicals, and Ni(II) porphyrin. pi. -anion radicals with some Ni(I) character

Journal Article · Wed Jan 16 04:00:00 EST 1991 · Journal of the American Chemical Society; (United States)

DOI:https://doi.org/10.1021/ja00002a019· OSTI ID:5234854

Kadish, K M; Franzen, M M; Han, B C; Araullo-McAdams, C; Sazou, D ^[1]

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1. Univ. of Houston, TX (USA)

The effect of temperature, porphyrin macrocycle, and solvent on the electroreduction of (P) Ni{sup II} where P is the dianion of meso-tetrakis(p-(diethylamino)phenyl)porphyrin (T(p-Et{sub 2}N)PP) or meso-tetrakis(o,o,m,m-tetrafluoro-p-(dimethylamino)phenyl)porphyrin (T(p-Me{sub 2}N)F{sub 4}PP) is reported. Both compounds were reduced by controlled potential electrolysis and characterized by ESR and UV-visible spectroscopy. The site of electron transfer varied as a function of experimental conditions and the stable electrogenerated products were assigned as Ni(I) porphyrins, Ni(II) porphyrin {pi}-anion radicals, or Ni(II) porphyrin {pi}-anion radicals with some Ni(I) character. Ni(I) ESR spectra were obtained for ((T(p-Et{sub 2}N)PP)Ni){sup {minus}} and ((T(p-Me{sub 2}N)F{sub 4}PP)Ni){sup {minus}} at low temperature in THF under a CO atmosphere as well as in DMF or pyridine under N{sub 2}. In contrast, ESR spectra of Ni(II) porphyrin {pi}-anion radicals or Ni(II) porphyrin {pi}-anion radicals with some Ni(I) character were obtained in THF under N{sub 2} at room and low temperature, respectively. ((T(p-Et{sub 2}N)PP)Ni){sup {minus}} catalytically reduces CH{sub 3}I at room temperature, consistent with the presence of some Ni(I) character in the reactive species.

• OSTI ID: 5234854
• Journal Information: Journal of the American Chemical Society; (United States), Journal Name: Journal of the American Chemical Society; (United States) Vol. 113:2; ISSN 0002-7863; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102* -- Chemical & Spectral Procedures
CARBOXYLIC ACIDS
COMPLEXES
ELECTRON SPIN RESONANCE
ELECTRON TRANSFER
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
MAGNETIC RESONANCE
MEASURING METHODS
MEDIUM TEMPERATURE
NICKEL COMPLEXES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PORPHYRINS
RESONANCE
TEMPERATURE EFFECTS
TRANSITION ELEMENT COMPLEXES
VOLTAMETRY