%0 Journal Article %1 Maji.2008b %A Maji, Somnath %A Sarkar, Biprajit %A Mobin, Shaikh M. %A Fiedler, Jan %A Urbanos, Francisco A. %A Jimenez-Aparicio, Reyes %A Kaim, Wolfgang %A Lahiri, Goutam Kumar. %D 2008 %J Inorganic Chemistry %K acetylacetonate acetylacetonato complex complex;dihydroxyanthraquinone crystal dinuclear electrochem electrochem;ruthenium magnetism prepn quinizarinato ruthenium structure %N 12 %P 5204--5211 %R 10.1021/ic800115q %T Valence-State Alternatives in Diastereoisomeric Complexes (acac)2Ru(m-QL)Ru(acac)2n (QL2- = 1,4-Dioxido-9,10-anthraquinone, n = +2, +1, 0, -1, -2) %V 47 %X The complexes (acac)2Ru(m-QL)Ru(acac)2n were obtained in neutral form (n = 0) as rac (1) and meso isomers (2). 2 Was crystd. for x-ray diffraction and its temp.-dependent magnetism studied. It contains two antiferromagnetically coupled ruthenium(III) ions, bridged by the quinizarine dianion QL2- (quinizarine = 1,4-dihydroxy-9,10-anthraquinone). The potential of both the ligand (QL0 $\rightarrow$ QL4-) and the metal complex fragment combination (acac)2RuII2 $\rightarrow$ (acac)2RuIV24+ to exist in five different redox states creates a large variety of combinations, which was assessed for the electrochem. reversibly accessible 2+, 1+, 0, 1-, 2- forms using cyclic voltammetry as well as EPR and UV-visible-NIR spectroelectrochem. The results for the two isomers are similar: Oxidn. to 1+ or 2+ causes the emergence of a near-IR band (1390 nm), without revealing an EPR response even at 4 K. Redn. to 1- or 2- produces an EPR signal, signifying metal-centered spin but no near-IR absorption. Tentatively, the authors assume metal-based oxidn. of (acac)2RuIII(m-QL2-)RuIII(acac)2 to a mixed-valent intermediate (acac)2RuIII(m-QL2-)RuIV(acac)2+ and ligand-centered redn. to a radical complex (acac)2RuIII(m-QL·3-)RuIII(acac)2- with antiferromagnetic three-spin interaction. on SciFinder(R)

@article{Maji.2008b, abstract = {The complexes [(acac)2Ru(\textgreek{m}-QL)Ru(acac)2]n were obtained in neutral form (n = 0) as rac (1) and meso isomers (2). 2 Was crystd. for x-ray diffraction and its temp.-dependent magnetism studied. It contains two antiferromagnetically coupled ruthenium(III) ions, bridged by the quinizarine dianion QL2- (quinizarine = 1,4-dihydroxy-9,10-anthraquinone). The potential of both the ligand (QL0 $\rightarrow$ QL4-) and the metal complex fragment combination [(acac)2RuII]2 $\rightarrow$ {[(acac)2RuIV]2}4+ to exist in five different redox states creates a large variety of combinations, which was assessed for the electrochem. reversibly accessible 2+, 1+, 0, 1-, 2- forms using cyclic voltammetry as well as EPR and UV-visible-NIR spectroelectrochem. The results for the two isomers are similar: Oxidn. to 1+ or 2+ causes the emergence of a near-IR band (1390 nm), without revealing an EPR response even at 4 K. Redn. to 1- or 2- produces an EPR signal, signifying metal-centered spin but no near-IR absorption. Tentatively, the authors assume metal-based oxidn. of [(acac)2RuIII(\textgreek{m}-QL2-)RuIII(acac)2] to a mixed-valent intermediate [(acac)2RuIII(\textgreek{m}-QL2-)RuIV(acac)2]+ and ligand-centered redn. to a radical complex [(acac)2RuIII(\textgreek{m}-QL·3-)RuIII(acac)2]- with antiferromagnetic three-spin interaction. [on SciFinder(R)]}, added-at = {2022-06-15T11:26:56.000+0200}, author = {Maji, Somnath and Sarkar, Biprajit and Mobin, Shaikh M. and Fiedler, Jan and Urbanos, Francisco A. and Jimenez-Aparicio, Reyes and Kaim, Wolfgang and Lahiri, Goutam Kumar.}, biburl = {https://puma.ub.uni-stuttgart.de/bibtex/254ebab6d9a753e2d1e0a29da96aa7389/huebleriac}, doi = {10.1021/ic800115q}, interhash = {011d2f7d34c697c5f369932792f074d9}, intrahash = {54ebab6d9a753e2d1e0a29da96aa7389}, issn = {0020-1669}, journal = {Inorganic Chemistry}, keywords = {acetylacetonate acetylacetonato complex complex;dihydroxyanthraquinone crystal dinuclear electrochem electrochem;ruthenium magnetism prepn quinizarinato ruthenium structure}, number = 12, pages = {5204--5211}, timestamp = {2022-06-15T09:26:56.000+0200}, title = {Valence-State Alternatives in Diastereoisomeric Complexes [(acac)2Ru(\textgreek{m}-QL)Ru(acac)2]n (QL2- = 1,4-Dioxido-9,10-anthraquinone, n = +2, +1, 0, -1, -2)}, volume = 47, year = 2008 }