Resolving the Two-Electron Process for the Couple (C5Me5)M(NN̂)Cl+/(C5Me5)M(NN̂) (M = Rh, Ir) into Two One-Electron Steps Using the 2,2'-Azobis(pyridine) NN̂ Ligand, Fast Scan Cyclovoltammetry, and Spectroelectrochemistry: Detection of Radicals instead of MII Intermediates
(C5Me5)M(abpy)Cl+ M = Rh, Ir; abpy = 2,2'-azobis(pyridine) are reduced to the coordinatively unsatd. compds. (C5Me5)M(abpy) via the EPR and UV/visible spectroelectrochem. detectable radical intermediates (C5Me5)MIII(abpy-I)Cl.bul.. Fast-scan cyclic voltammetry allowed the authors to establish the electrochem. potentials. This stepwise mechanism differs from the two-electron processes obsd. for the analogous systems (C5Me5)M(NN̂)Cl+/(C5Me5)M(NN̂) with NN̂ = 2,2'-bipyridines, bidiazines, 1,4-diaza-1,3-butadienes. In contrast to Co systems such as (C5Me5)Co(bpy)Cl+ the 1-electron redn. does not involve the metal. The role of the abpy ligand as an intermediate 1-electron storage component for a metal-centered two-electron process is discussed. Further redn. of (C5Me5)M(abpy) to (C5Me5)MII(abpy-II)- at very neg. potentials illustrates the extremely strong p back-donation from the 14-valence-electron fragments (C5Me5)M (M = Rh, Ir). on SciFinder(R)
%0 Journal Article
%1 Kaim.2003b
%A Kaim, Wolfgang
%A Reinhardt, Ralf
%A Greulich, Stefan
%A Fiedler, Jan.
%D 2003
%J Organometallics
%K ESR;rhodium UV azobispyridine complex electrochem intermediate iridium prepn radical redox rhodium spectroelectrochem
%N 11
%P 2240--2244
%R 10.1021/om020860j
%T Resolving the Two-Electron Process for the Couple (C5Me5)M(NN̂)Cl+/(C5Me5)M(NN̂) (M = Rh, Ir) into Two One-Electron Steps Using the 2,2'-Azobis(pyridine) NN̂ Ligand, Fast Scan Cyclovoltammetry, and Spectroelectrochemistry: Detection of Radicals instead of MII Intermediates
%V 22
%X (C5Me5)M(abpy)Cl+ M = Rh, Ir; abpy = 2,2'-azobis(pyridine) are reduced to the coordinatively unsatd. compds. (C5Me5)M(abpy) via the EPR and UV/visible spectroelectrochem. detectable radical intermediates (C5Me5)MIII(abpy-I)Cl.bul.. Fast-scan cyclic voltammetry allowed the authors to establish the electrochem. potentials. This stepwise mechanism differs from the two-electron processes obsd. for the analogous systems (C5Me5)M(NN̂)Cl+/(C5Me5)M(NN̂) with NN̂ = 2,2'-bipyridines, bidiazines, 1,4-diaza-1,3-butadienes. In contrast to Co systems such as (C5Me5)Co(bpy)Cl+ the 1-electron redn. does not involve the metal. The role of the abpy ligand as an intermediate 1-electron storage component for a metal-centered two-electron process is discussed. Further redn. of (C5Me5)M(abpy) to (C5Me5)MII(abpy-II)- at very neg. potentials illustrates the extremely strong p back-donation from the 14-valence-electron fragments (C5Me5)M (M = Rh, Ir). on SciFinder(R)
@article{Kaim.2003b,
abstract = {[(C5Me5)M(abpy)Cl]+ [M = Rh, Ir; abpy = 2,2'-azobis(pyridine)] are reduced to the coordinatively unsatd. compds. [(C5Me5)M(abpy)] via the EPR and UV/visible spectroelectrochem. detectable radical intermediates [(C5Me5)MIII(abpy-I)Cl].bul.. Fast-scan cyclic voltammetry allowed the authors to establish the electrochem. potentials. This stepwise mechanism differs from the two-electron processes obsd. for the analogous systems [(C5Me5)M(NN̂)Cl]+/[(C5Me5)M(NN̂)] with NN̂ = 2,2'-bipyridines, bidiazines, 1,4-diaza-1,3-butadienes. In contrast to Co systems such as [(C5Me5)Co(bpy)Cl]+ the 1-electron redn. does not involve the metal. The role of the abpy ligand as an intermediate 1-electron storage component for a metal-centered two-electron process is discussed. Further redn. of [(C5Me5)M(abpy)] to [(C5Me5)MII(abpy-II)]- at very neg. potentials illustrates the extremely strong \textgreek{p} back-donation from the 14-valence-electron fragments (C5Me5)M (M = Rh, Ir). [on SciFinder(R)]},
added-at = {2019-07-15T13:41:23.000+0200},
author = {Kaim, Wolfgang and Reinhardt, Ralf and Greulich, Stefan and Fiedler, Jan.},
biburl = {https://puma.ub.uni-stuttgart.de/bibtex/245fada6ab064c52ad120e777e101d15d/b_schwederski},
doi = {10.1021/om020860j},
interhash = {daba6141d9898aaba4ea1beaa2a08061},
intrahash = {45fada6ab064c52ad120e777e101d15d},
issn = {0276-7333},
journal = {Organometallics},
keywords = {ESR;rhodium UV azobispyridine complex electrochem intermediate iridium prepn radical redox rhodium spectroelectrochem},
number = 11,
pages = {2240--2244},
timestamp = {2019-07-15T11:42:10.000+0200},
title = {Resolving the Two-Electron Process for the Couple [(C5Me5)M(NN̂)Cl]+/[(C5Me5)M(NN̂)] (M = Rh, Ir) into Two One-Electron Steps Using the 2,2'-Azobis(pyridine) NN̂ Ligand, Fast Scan Cyclovoltammetry, and Spectroelectrochemistry: Detection of Radicals instead of MII Intermediates},
volume = 22,
year = 2003
}