%0 Journal Article %1 Das.2011d %A Das, Dipanwita %A Sarkar, Biprajit %A Mondal, Tapan Kumar %A Mobin, Shaikh M. %A Fiedler, Jan %A Kaim, Wolfgang %A Lahiri, Goutam Kumar. %D 2011 %J Inorganic Chemistry %K ESR NIR complex complex;osmium crystal cyclic iminobenzoquinone osmium phenylazopyridine prepn spectra structure voltammetry %N 15 %P 7090--7098 %R 10.1021/ic200615s %T Oxidation State Analysis of a Four-Component Redox Series [Os(pap)2(Q)]n Involving Two Different Non-Innocent Ligands on a Redox-Active Transition Metal %V 50 %X Complexes [Os(pap)2(Q)] (1-4) were obtained and structurally characterized for pap = 2-phenylazopyridine and Q = 4,6-di-tert-butyl-N-aryl-o-iminobenzoquinone (aryl = Ph (1), 3,5-dichlorophenyl (2), 3,5-dimethoxyphenyl (3), or 3,5-di-tert-butylphenyl (4)). The oxidized form (3)(ClO4)2 was also crystallog. characterized while the odd-electron intermediates [Os(pap)2(Q)]+ (1+-4+) and [Os(pap)2(Q)]- (2-) were studied by EPR and UV-visible-NIR spectroelectrochem. in conjunction with d. functional theory (DFT) spin d. and time-dependent DFT (TD-DFT) calcns. The results from the structural, spectroscopic, and electrochem. expts. and from the computational studies allow for the assignments [OsII(pap0)2(Q0)]2+, [OsII(pap0)2(Q·-)]+, [OsIV(pap·-)2(Q2-)], and [OsII(pap·-)(pap0)(Q2-)]-, with comproportionation consts. Kc $\approx$ 103.5, 1010, 1018, and 105, resp. The redox potentials and the comproportionation consts. exhibit similarities and differences between Ru and Os analogs. While the Q-based redox reactions show identical potentials, the more metal-involving processes exhibit cathodic shifts for the osmium systems, leading to distinctly different comproportionation consts. for some intermediates, esp. to a stabilization of the neutral osmium compds. described. The example [Os(pap)2(Q)]n illustrates esp. the power of combined structural and EPR anal. with support from DFT towards the valence state description of transition metal complexes incorporating redox non-innocent ligands. [on SciFinder(R)]

@article{Das.2011d, abstract = {Complexes [Os(pap)2(Q)] (1-4) were obtained and structurally characterized for pap = 2-phenylazopyridine and Q = 4,6-di-tert-butyl-N-aryl-o-iminobenzoquinone (aryl = Ph (1), 3,5-dichlorophenyl (2), 3,5-dimethoxyphenyl (3), or 3,5-di-tert-butylphenyl (4)). The oxidized form (3)(ClO4)2 was also crystallog. characterized while the odd-electron intermediates [Os(pap)2(Q)]+ (1+-4+) and [Os(pap)2(Q)]- (2-) were studied by EPR and UV-visible-NIR spectroelectrochem. in conjunction with d. functional theory (DFT) spin d. and time-dependent DFT (TD-DFT) calcns. The results from the structural, spectroscopic, and electrochem. expts. and from the computational studies allow for the assignments [OsII(pap0)2(Q0)]2+, [OsII(pap0)2(Q·-)]+, [OsIV(pap·-)2(Q2-)], and [OsII(pap·-)(pap0)(Q2-)]-, with comproportionation consts. Kc $\approx$ 103.5, 1010, 1018, and 105, resp. The redox potentials and the comproportionation consts. exhibit similarities and differences between Ru and Os analogs. While the Q-based redox reactions show identical potentials, the more metal-involving processes exhibit cathodic shifts for the osmium systems, leading to distinctly different comproportionation consts. for some intermediates, esp. to a stabilization of the neutral osmium compds. described. The example [Os(pap)2(Q)]n illustrates esp. the power of combined structural and EPR anal. with support from DFT towards the valence state description of transition metal complexes incorporating redox non-innocent ligands. [on SciFinder(R)]}, added-at = {2022-06-15T11:26:56.000+0200}, author = {Das, Dipanwita and Sarkar, Biprajit and Mondal, Tapan Kumar and Mobin, Shaikh M. and Fiedler, Jan and Kaim, Wolfgang and Lahiri, Goutam Kumar.}, biburl = {https://puma.ub.uni-stuttgart.de/bibtex/23529db0d6917ca4020dfa4557afb95cf/huebleriac}, doi = {10.1021/ic200615s}, interhash = {0dddaf4bb1578be6a000f5c4e065932d}, intrahash = {3529db0d6917ca4020dfa4557afb95cf}, issn = {0020-1669}, journal = {Inorganic Chemistry}, keywords = {ESR NIR complex complex;osmium crystal cyclic iminobenzoquinone osmium phenylazopyridine prepn spectra structure voltammetry}, number = 15, pages = {7090--7098}, timestamp = {2022-06-15T09:26:56.000+0200}, title = {Oxidation State Analysis of a Four-Component Redox Series [Os(pap)2(Q)]n Involving Two Different Non-Innocent Ligands on a Redox-Active Transition Metal}, volume = 50, year = 2011 }