%0 Journal Article %1 Hazari.2016 %A Hazari, Arijit Singha %A Paretzki, Alexa %A Fiedler, Jan %A Zalis, Stanislav %A Kaim, Wolfgang %A Lahiri, Goutam Kumar. %D 2016 %J Dalton Transactions %K bipyridine complex crystal electrochem mol optimization osmium oxidophenalenone phenylazopyridine phenylazopyridine;ESR phenylazopyridine;osmium prepn structure %N 45 %P 18241--18251 %R 10.1039/C6DT03764J %T Different manifestations of enhanced p-acceptor ligation at every redox level of [Os(9-OP)L2]n, n = 2+, +, 0, - (9-OP- = 9-oxidophenalenone and L = bpy or pap) %V 45 %X The title complexes were isolated as structurally characterized compds. [OsII(9-OP)L2]ClO4, L = 2,2'-bipyridine (bpy) or 2-phenylazopyridine (pap), and were compared with ruthenium analogs. A reversible one-electron oxidn. and up to three redn. processes were obsd. by voltammetry (CV, DPV) and spectroelectrochem. (UV-vis-NIR, partially EPR). Supporting calcns. (DFT, TD-DFT) were used to assess the oxidn. state combinations of the different redox active ligands and of the metal, revealing the effects of Os vs. Ru exchange and of bpy vs. pap acceptor ligation. Several unexpected consequences of these variations were obsd. for members of the new osmium-contg. redox series. Remarkably, the EPR results exhibit a clear dichotomy between the complex ion [OsIII(9-OP-)(bpy)2]2+ and the radical species [OsII(9-OP)̇(pap)2]2+, which has not been similarly obsd. for the analogous [RuIII(9-OP-)L2]2+ systems. This difference, unprecedented for 5dn systems, is attributed to the superior stabilization of the OsII state by the strongly p-accepting pap ligands. The reduced forms [OsII(9-OP-)(pap ̇-)(pap)] and [OsII(9-OP-)(pap ̇-)2]- exhibit strong inter-ligand interactions, leading to spin isomers and electron hopping. [on SciFinder(R)]

@article{Hazari.2016, abstract = {The title complexes were isolated as structurally characterized compds. [OsII(9-OP)L2]ClO4, L = 2,2'-bipyridine (bpy) or 2-phenylazopyridine (pap), and were compared with ruthenium analogs. A reversible one-electron oxidn. and up to three redn. processes were obsd. by voltammetry (CV, DPV) and spectroelectrochem. (UV-vis-NIR, partially EPR). Supporting calcns. (DFT, TD-DFT) were used to assess the oxidn. state combinations of the different redox active ligands and of the metal, revealing the effects of Os vs. Ru exchange and of bpy vs. pap acceptor ligation. Several unexpected consequences of these variations were obsd. for members of the new osmium-contg. redox series. Remarkably, the EPR results exhibit a clear dichotomy between the complex ion [OsIII(9-OP-)(bpy)2]2+ and the radical species [OsII(9-OP)̇(pap)2]2+, which has not been similarly obsd. for the analogous [RuIII(9-OP-)L2]2+ systems. This difference, unprecedented for 5dn systems, is attributed to the superior stabilization of the OsII state by the strongly \textgreek{p}-accepting pap ligands. The reduced forms [OsII(9-OP-)(pap ̇-)(pap)] and [OsII(9-OP-)(pap ̇-)2]- exhibit strong inter-ligand interactions, leading to spin isomers and electron hopping. [on SciFinder(R)]}, added-at = {2022-06-15T11:26:56.000+0200}, author = {Hazari, Arijit Singha and Paretzki, Alexa and Fiedler, Jan and Zalis, Stanislav and Kaim, Wolfgang and Lahiri, Goutam Kumar.}, biburl = {https://puma.ub.uni-stuttgart.de/bibtex/274e8cc04a4b422dcc26ff997e4a1d05a/huebleriac}, doi = {10.1039/C6DT03764J}, interhash = {f070a3b874bba83d213421f33898b895}, intrahash = {74e8cc04a4b422dcc26ff997e4a1d05a}, issn = {1477-9226}, journal = {Dalton Transactions}, keywords = {bipyridine complex crystal electrochem mol optimization osmium oxidophenalenone phenylazopyridine phenylazopyridine;ESR phenylazopyridine;osmium prepn structure}, number = 45, pages = {18241--18251}, timestamp = {2022-06-15T09:26:56.000+0200}, title = {Different manifestations of enhanced \textgreek{p}-acceptor ligation at every redox level of [Os(9-OP)L2]n, n = 2+, +, 0, - (9-OP- = 9-oxidophenalenone and L = bpy or pap)}, volume = 45, year = 2016 }