%0 Journal Article %1 Paretzki.2014 %A Paretzki, Alexa %A Bubrin, Martina %A Fiedler, Jan %A Zalis, Stanislav %A Kaim, Wolfgang. %D 2014 %J Chemistry - A European Journal %K activity;nickel complex complex;hemilabile crystal electronic iminobenzoquinone ligand methylthiomethylphenyl nickel noninnocent prepn redox spectroelectrochem structure %N 18 %P 5414--5422 %R 10.1002/chem.201304316 %T Correlated Coordination and Redox Activity of a Hemilabile Noninnocent Ligand in Nickel Complexes %V 20 %X Ni(QM)2, QM = 4,6-di-tert-butyl-N-(2-methylthiomethylphenyl)-o-iminobenzoquinone, is a singlet diradical species with approx. planar configuration at the tetracoordinate metal atom and without any Ni-S bonding interaction. One-electron oxidn. results in addnl. 2-fold Ni-S coordination (dNi-S$\approx$2.38 \AA) to produce a complex cation of Ni(QM)2(PF6) with hexacoordinate NiII and two distinctly different mer-configurated tridentate ligands. The O,O'-trans arrangement in the neutral precursor is changed to an O,O'-cis configuration in the cation. The EPR signal of Ni(QM)2(PF6) has a very large g anisotropy and the magnetic measurements indicate an S = 3/2 state. The dication was structurally characterized as Ni(QM)2(ClO4)2 to exhibit a similar NiN2O2S2 framework as the monocation. However, the two tridentate (O,N,S) ligands are now equiv. according to NiII(QM0)22+. Cyclic voltammetry reflects the qual. structure change on the 1st, but not the 2nd oxidn. of Ni(QM)2, and spectroelectrochem. reveals a pronounced dependence of the 800-900 nm absorption on the solvent and counterion. Redn. of the neutral form occurs in an electrochem. reversible step to yield an anion with an intense near-IR absorption at 1345 nm (e = 10400 M-1 cm-1) and a conventional g factor splitting for a largely metal-based spin (S = 1/2 ), suggesting a (QM.-)NiII(QM2-)- configuration with a tetracoordinate metal atom with antiferromagnetic NiII-(QM.-) interactions and symmetry-allowed ligand-to-ligand intervalence charge transfer (LLIVCT). Calcns. were used to understand the Ni-S binding activity as induced by remote electron transfer at the iminobenzoquinone redox system. on SciFinder(R)

@article{Paretzki.2014, abstract = {[Ni(QM)2], QM = 4,6-di-tert-butyl-N-(2-methylthiomethylphenyl)-o-iminobenzoquinone, is a singlet diradical species with approx. planar configuration at the tetracoordinate metal atom and without any Ni-S bonding interaction. One-electron oxidn. results in addnl. 2-fold Ni-S coordination (dNi-S$\approx$2.38 {\AA}) to produce a complex cation of [Ni(QM)2](PF6) with hexacoordinate NiII and two distinctly different mer-configurated tridentate ligands. The O,O'-trans arrangement in the neutral precursor is changed to an O,O'-cis configuration in the cation. The EPR signal of [Ni(QM)2](PF6) has a very large g anisotropy and the magnetic measurements indicate an S = 3/2 state. The dication was structurally characterized as [Ni(QM)2](ClO4)2 to exhibit a similar NiN2O2S2 framework as the monocation. However, the two tridentate (O,N,S) ligands are now equiv. according to [NiII(QM0)2]2+. Cyclic voltammetry reflects the qual. structure change on the 1st, but not the 2nd oxidn. of [Ni(QM)2], and spectroelectrochem. reveals a pronounced dependence of the 800-900 nm absorption on the solvent and counterion. Redn. of the neutral form occurs in an electrochem. reversible step to yield an anion with an intense near-IR absorption at 1345 nm (\textgreek{e} = 10400 M-1 cm-1) and a conventional g factor splitting for a largely metal-based spin (S = 1/2 ), suggesting a [(QM.-)NiII(QM2-)]- configuration with a tetracoordinate metal atom with antiferromagnetic NiII-(QM.-) interactions and symmetry-allowed ligand-to-ligand intervalence charge transfer (LLIVCT). Calcns. were used to understand the Ni-S binding activity as induced by remote electron transfer at the iminobenzoquinone redox system. [on SciFinder(R)]}, added-at = {2019-07-15T13:41:23.000+0200}, author = {Paretzki, Alexa and Bubrin, Martina and Fiedler, Jan and Zalis, Stanislav and Kaim, Wolfgang.}, biburl = {https://puma.ub.uni-stuttgart.de/bibtex/256029d8f4b99c839b5907fb3d7a5976b/b_schwederski}, doi = {10.1002/chem.201304316}, interhash = {a6439a064d510f83184c459c883aadd7}, intrahash = {56029d8f4b99c839b5907fb3d7a5976b}, issn = {0947-6539}, journal = {Chemistry - A European Journal}, keywords = {activity;nickel complex complex;hemilabile crystal electronic iminobenzoquinone ligand methylthiomethylphenyl nickel noninnocent prepn redox spectroelectrochem structure}, number = 18, pages = {5414--5422}, timestamp = {2019-07-15T11:42:10.000+0200}, title = {Correlated Coordination and Redox Activity of a Hemilabile Noninnocent Ligand in Nickel Complexes}, volume = 20, year = 2014 }