%0 Journal Article %1 Krejcik.1993 %A Krejcik, Michael %A Zalis, Stanislav %A Klima, Jiri %A Sykora, David %A Matheis, Walter %A Klein, Axel %A Kaim, Wolfgang. %D 1993 %J Inorganic Chemistry %K azabispyridine bipyridine electrochem isomer isomer;electronic redn ruthenium spectra %N 15 %P 3362--3368 %R 10.1021/ic00067a029 %T 2,2'-Azobis(pyridine) (abpy) as a multiply reducible tetradentate ligand. EPR evidence for the configurational dependence of intramolecular electron transfer in the stereoisomeric tris-chelate ruthenium complexes [Ru(abpy)n(bpy)3-n]m (n = 2, 3; m = 2+ to 3-) %V 32 %X Fac- and mer-[Ru(abpy)3]2+ (abpy = 2,2'-azobis(pyridine) and 2 out of the 3 possible diastereoisomers of [Ru(abpy)2(bpy)]2+ were isolated via HPLC and identified by their 1H NMR spectra. Electrochem. potentials for several 1-electron redn. steps and UV/visible spectroelectrochem. features vary to a small but detectable degree for the resp. pairs of isomers. The absence of a room-temp. EPR signal for 1 of the 2 isolated isomers of [RuII(abpy-)(abpy)(bpy)].bul.+ demonstrates the structural requirements for intramol. electron transfer. A 99,101Ru EPR hyperfine coupling of $\sim$0.8 mT was established for the previously reported radical ion [Ru(abpy)(bpy)2].bul.+. The free a-azimino chelate is in mononuclear complexes of abpy render these systems suitable for the construction of polynuclear compds. The exceptional p-acceptor capability of abpy is illustrated by the reversible acceptance of $\geq$8 electrons by [(Ru(bpy)2]2(μ,η4-abpy)n. [on SciFinder(R)]

@article{Krejcik.1993, abstract = {Fac- and mer-[Ru(abpy)3]2+ (abpy = 2,2'-azobis(pyridine) and 2 out of the 3 possible diastereoisomers of [Ru(abpy)2(bpy)]2+ were isolated via HPLC and identified by their 1H NMR spectra. Electrochem. potentials for several 1-electron redn. steps and UV/visible spectroelectrochem. features vary to a small but detectable degree for the resp. pairs of isomers. The absence of a room-temp. EPR signal for 1 of the 2 isolated isomers of [RuII(abpy-)(abpy)(bpy)].bul.+ demonstrates the structural requirements for intramol. electron transfer. A 99,101Ru EPR hyperfine coupling of $\sim$0.8 mT was established for the previously reported radical ion [Ru(abpy)(bpy)2].bul.+. The free \textgreek{a}-azimino chelate is in mononuclear complexes of abpy render these systems suitable for the construction of polynuclear compds. The exceptional \textgreek{p}-acceptor capability of abpy is illustrated by the reversible acceptance of $\geq$8 electrons by {[(Ru(bpy)2]2(μ,η4-abpy)}n. [on SciFinder(R)]}, added-at = {2022-06-15T11:26:56.000+0200}, author = {Krejcik, Michael and Zalis, Stanislav and Klima, Jiri and Sykora, David and Matheis, Walter and Klein, Axel and Kaim, Wolfgang.}, biburl = {https://puma.ub.uni-stuttgart.de/bibtex/2312cc76c16ed3d77cf119eef8e253192/huebleriac}, doi = {10.1021/ic00067a029}, interhash = {5836afeb600585598041b0ef66f14bbe}, intrahash = {312cc76c16ed3d77cf119eef8e253192}, issn = {0020-1669}, journal = {Inorganic Chemistry}, keywords = {azabispyridine bipyridine electrochem isomer isomer;electronic redn ruthenium spectra}, number = 15, pages = {3362--3368}, timestamp = {2022-06-15T09:26:56.000+0200}, title = {2,2'-Azobis(pyridine) (abpy) as a multiply reducible tetradentate ligand. EPR evidence for the configurational dependence of intramolecular electron transfer in the stereoisomeric tris-chelate ruthenium complexes [Ru(abpy)n(bpy)3-n]m (n = 2, 3; m = 2+ to 3-)}, volume = 32, year = 1993 }