A comprehensive ESR study of 11 mononuclear and 5 dinuclear singly reduced tris(a-diimine)ruthenium (II) complexes of the general formulas [(L)3Ru]+.bul., [(L)(bpy)2Ru]+.bul., and [(bpy)2Ru(m-L)Ru(bpy)2]3+.bul.; 2,2'-bipyridine; L, other a-diimine) shows a variety of g factors and spectral resoln. All paramagnetic species are true anion-radical complexes with little g anisotropy and relatively small but characteristically pos. differences g(ligand radical) - g(complex). The variations correlate with the calcd. properties. of the ligands and with spectroscopic and electrochem. data for the diamagnetic precursor complexes. In particular, the g shifts depend (1) on the extent of metal-ligand interaction and (2) on the energy differences between the singly occupied and neighboring unoccupied or completely filled orbitals. Virtually complete localization of the unpaired electron on the better P-accepting ligang L has been established for the mono- and dinuclear heteroleptic systems, while fast spin exchange on the ESR time scale is evident from the ESR line width of all singly reduced homoleptic complexes. [on SciFinder(R)]
%0 Journal Article
%1 Kaim.1990
%A Kaim, Wolfgang
%A Ernst, Sylvia
%A Kasack, Volker.
%D 1990
%J Journal of the American Chemical Society
%K ESR ESR;homoleptic complex complex;heteroleptic diimine ruthenium
%N 1
%P 173--178
%R 10.1021/ja00157a028
%T ESR of homo- and heteroleptic mono- and dinuclear tris(a-diimine)ruthenium radical complexes
%V 112
%X A comprehensive ESR study of 11 mononuclear and 5 dinuclear singly reduced tris(a-diimine)ruthenium (II) complexes of the general formulas [(L)3Ru]+.bul., [(L)(bpy)2Ru]+.bul., and [(bpy)2Ru(m-L)Ru(bpy)2]3+.bul.; 2,2'-bipyridine; L, other a-diimine) shows a variety of g factors and spectral resoln. All paramagnetic species are true anion-radical complexes with little g anisotropy and relatively small but characteristically pos. differences g(ligand radical) - g(complex). The variations correlate with the calcd. properties. of the ligands and with spectroscopic and electrochem. data for the diamagnetic precursor complexes. In particular, the g shifts depend (1) on the extent of metal-ligand interaction and (2) on the energy differences between the singly occupied and neighboring unoccupied or completely filled orbitals. Virtually complete localization of the unpaired electron on the better P-accepting ligang L has been established for the mono- and dinuclear heteroleptic systems, while fast spin exchange on the ESR time scale is evident from the ESR line width of all singly reduced homoleptic complexes. [on SciFinder(R)]
@article{Kaim.1990,
abstract = {A comprehensive ESR study of 11 mononuclear and 5 dinuclear singly reduced tris(\textgreek{a}-diimine)ruthenium (II) complexes of the general formulas [(L)3Ru]+.bul., [(L)(bpy)2Ru]+.bul., and [(bpy)2Ru(\textgreek{m}-L)Ru(bpy)2]3+.bul.; 2,2'-bipyridine; L, other \textgreek{a}-diimine) shows a variety of g factors and spectral resoln. All paramagnetic species are true anion-radical complexes with little g anisotropy and relatively small but characteristically pos. differences g(ligand radical) - g(complex). The variations correlate with the calcd. properties. of the ligands and with spectroscopic and electrochem. data for the diamagnetic precursor complexes. In particular, the g shifts depend (1) on the extent of metal-ligand interaction and (2) on the energy differences between the singly occupied and neighboring unoccupied or completely filled orbitals. Virtually complete localization of the unpaired electron on the better \textgreek{P}-accepting ligang L has been established for the mono- and dinuclear heteroleptic systems, while fast spin exchange on the ESR time scale is evident from the ESR line width of all singly reduced homoleptic complexes. [on SciFinder(R)]},
added-at = {2022-06-15T11:26:56.000+0200},
author = {Kaim, Wolfgang and Ernst, Sylvia and Kasack, Volker.},
biburl = {https://puma.ub.uni-stuttgart.de/bibtex/2219be1c08bbf0d1a459e938e702e343f/huebleriac},
doi = {10.1021/ja00157a028},
interhash = {d6050fa633953785df1daa1cbd2039b8},
intrahash = {219be1c08bbf0d1a459e938e702e343f},
issn = {0002-7863},
journal = {Journal of the American Chemical Society},
keywords = {ESR ESR;homoleptic complex complex;heteroleptic diimine ruthenium},
number = 1,
pages = {173--178},
timestamp = {2022-06-15T09:26:56.000+0200},
title = {ESR of homo- and heteroleptic mono- and dinuclear tris(\textgreek{a}-diimine)ruthenium radical complexes},
volume = 112,
year = 1990
}
