%0 Journal Article %1 Berger.2000 %A Berger, Sascha %A Klein, Axel %A Wanner, Matthias %A Kaim, Wolfgang %A Fiedler, Jan. %D 2000 %J Inorganic Chemistry %K bpip bxip chloro cyclopentadienyl diiminopyrazine electrochem iridium mixed pentamethylcyclopentadienyl pentamethylcyclopentadienyl;iminoethyl prepn pyrazine redn redn;ESR rhodium valent %N 12 %P 2516--2521 %R 10.1021/ic991110d %T Electron Paramagnetic Resonance and Spectroscopic Characteristics of Electrogenerated Mixed-Valent Systems [(h5-C5Me5)M(m-L)M(h5-C5Me5)]+ (M = Rh, Ir; L = 2,5-Diiminopyrazines) in Relation to the Radicals [(h5-C5Me5)ClM(m-L)MCl(h5-C5Me5)]+ and [(h5-C5Me5)M(m-L)MCl(h5-C5Me5)]2+ %V 39 %X Electrochem. redn. of the dinuclear [(h5-C5Me5)ClM(m-L)MCl(h5-C5Me5)]2+ ions (M = Rh, Ir; L = 2,5-bis(1-phenyliminoethyl)pyrazine (bpip) and 2,5-bis[1-(2,6-dimethylphenyl)iminoethyl]pyrazine (bxip)) proceeds via the paramagnetic intermediates [(h5-C5Me5)ClM(m-L)MCl(h5-C5Me5)]+ (L = bpip) or [(h5-C5Me5)M(m-L)MCl(h5-C5Me5)]2+ (L = bxip) and [(h5-C5Me5)M(m-L)M(h5-C5Me5)]+. Whereas the first is clearly a radical species with a small g anisotropy, the chloride-free cations are distinguished by structured intervalence charge transfer (IVCT) bands in the near-IR region and by rhombic ESR features between g = 1.9 and g = 2.3, which suggests considerable metal participation at the singly occupied MO. Alternatives for the d configuration assignment and for the role of the bisbidentate-conjugated bridging ligands will be discussed. The main difference between bpip and bxip systems is the destabilization of the chloride-contg. forms through the bxip ligand for reasons of steric interference. [on SciFinder(R)]

@article{Berger.2000, abstract = {Electrochem. redn. of the dinuclear [(\textgreek{h}5-C5Me5)ClM(\textgreek{m}-L)MCl(\textgreek{h}5-C5Me5)]2+ ions (M = Rh, Ir; L = 2,5-bis(1-phenyliminoethyl)pyrazine (bpip) and 2,5-bis[1-(2,6-dimethylphenyl)iminoethyl]pyrazine (bxip)) proceeds via the paramagnetic intermediates [(\textgreek{h}5-C5Me5)ClM(\textgreek{m}-L)MCl(\textgreek{h}5-C5Me5)]+ (L = bpip) or [(\textgreek{h}5-C5Me5)M(\textgreek{m}-L)MCl(\textgreek{h}5-C5Me5)]2+ (L = bxip) and [(\textgreek{h}5-C5Me5)M(\textgreek{m}-L)M(\textgreek{h}5-C5Me5)]+. Whereas the first is clearly a radical species with a small g anisotropy, the chloride-free cations are distinguished by structured intervalence charge transfer (IVCT) bands in the near-IR region and by rhombic ESR features between g = 1.9 and g = 2.3, which suggests considerable metal participation at the singly occupied MO. Alternatives for the d configuration assignment and for the role of the bisbidentate-conjugated bridging ligands will be discussed. The main difference between bpip and bxip systems is the destabilization of the chloride-contg. forms through the bxip ligand for reasons of steric interference. [on SciFinder(R)]}, added-at = {2022-06-15T11:26:56.000+0200}, author = {Berger, Sascha and Klein, Axel and Wanner, Matthias and Kaim, Wolfgang and Fiedler, Jan.}, biburl = {https://puma.ub.uni-stuttgart.de/bibtex/27754a47c08ab2109f07ba651abf8dce0/huebleriac}, doi = {10.1021/ic991110d}, interhash = {f87d5dc8a0c2e38dc20c77403983404c}, intrahash = {7754a47c08ab2109f07ba651abf8dce0}, issn = {0020-1669}, journal = {Inorganic Chemistry}, keywords = {bpip bxip chloro cyclopentadienyl diiminopyrazine electrochem iridium mixed pentamethylcyclopentadienyl pentamethylcyclopentadienyl;iminoethyl prepn pyrazine redn redn;ESR rhodium valent}, number = 12, pages = {2516--2521}, timestamp = {2022-06-15T09:26:56.000+0200}, title = {Electron Paramagnetic Resonance and Spectroscopic Characteristics of Electrogenerated Mixed-Valent Systems [(\textgreek{h}5-C5Me5)M(\textgreek{m}-L)M(\textgreek{h}5-C5Me5)]+ (M = Rh, Ir; L = 2,5-Diiminopyrazines) in Relation to the Radicals [(\textgreek{h}5-C5Me5)ClM(\textgreek{m}-L)MCl(\textgreek{h}5-C5Me5)]+ and [(\textgreek{h}5-C5Me5)M(\textgreek{m}-L)MCl(\textgreek{h}5-C5Me5)]2+}, volume = 39, year = 2000 }