%0 Journal Article %1 Sarkar.2003 %A Sarkar, Biprajit %A Kaim, Wolfgang %A Klein, Axel %A Schwederski, Brigitte %A Fiedler, Jan %A Duboc-Toia, Carole %A Lahiri, Goutam K. %D 2003 %J Inorganic Chemistry %K complex osmium pyridyl reaction redox spectroscopy spectroscopy;ruthenium synthesis tetrazine thienyl %N 20 %P 6172--6174 %R 10.1021/ic034105p %T What a Difference Ancillary Thienyl Makes: Unexpected Additional Stabilization of the Diruthenium(III,II) but Not the Diosmium(III,II) Mixed-Valent State in Tetrazine Ligand-Bridged Complexes %V 42 %X The Ru2III,II mixed-valent state is strongly stabilized in [(bpy)2Ru(m-bttz)Ru(bpy)2]5+ (35+), bttz = 3,6-bis(2-thienyl)-1,2,4,5-tetrazine, as evident from lowered oxidn. potentials and isolability, a strongly increased comproportionation const. Kc = 1016.6, and a high-energy intervalence charge transfer band at 10100 cm-1. Curiously, no such effects were obsd. for the diosmium(III,II) analog, whereas the related systems [(bpy)2M(m-bmptz)M(bpy)2]5+, bmptz = 3,6-bis(4-methyl-2-pyridyl)-1,2,4,5-tetrazine, exhibit conventional behavior, i.e., a slightly higher Kc value of the Os2III,II analog. EPR signals were obsd. at 4 K for 35+ but not for the other mixed-valent species, and high-frequency (285 GHz). EPR was employed to study the diruthenium(II) radical complexes 23+ and 33+. [on SciFinder(R)]

@article{Sarkar.2003, abstract = {The Ru2III,II mixed-valent state is strongly stabilized in [(bpy)2Ru(\textgreek{m}-bttz)Ru(bpy)2]5+ (35+), bttz = 3,6-bis(2-thienyl)-1,2,4,5-tetrazine, as evident from lowered oxidn. potentials and isolability, a strongly increased comproportionation const. Kc = 1016.6, and a high-energy intervalence charge transfer band at 10100 cm-1. Curiously, no such effects were obsd. for the diosmium(III,II) analog, whereas the related systems [(bpy)2M(\textgreek{m}-bmptz)M(bpy)2]5+, bmptz = 3,6-bis(4-methyl-2-pyridyl)-1,2,4,5-tetrazine, exhibit conventional behavior, i.e., a slightly higher Kc value of the Os2III,II analog. EPR signals were obsd. at 4 K for 35+ but not for the other mixed-valent species, and high-frequency (285 GHz). EPR was employed to study the diruthenium(II) radical complexes 23+ and 33+. [on SciFinder(R)]}, added-at = {2019-07-15T13:41:23.000+0200}, author = {Sarkar, Biprajit and Kaim, Wolfgang and Klein, Axel and Schwederski, Brigitte and Fiedler, Jan and Duboc-Toia, Carole and Lahiri, Goutam K.}, biburl = {https://puma.ub.uni-stuttgart.de/bibtex/2cb50f23d51829aa0ee752b07c9b83a6a/b_schwederski}, doi = {10.1021/ic034105p}, interhash = {0b7eb627f17ab06afad64204aa9942cd}, intrahash = {cb50f23d51829aa0ee752b07c9b83a6a}, issn = {0020-1669}, journal = {Inorganic Chemistry}, keywords = {complex osmium pyridyl reaction redox spectroscopy spectroscopy;ruthenium synthesis tetrazine thienyl}, number = 20, pages = {6172--6174}, timestamp = {2019-07-15T11:42:10.000+0200}, title = {What a Difference Ancillary Thienyl Makes: Unexpected Additional Stabilization of the Diruthenium(III,II) but Not the Diosmium(III,II) Mixed-Valent State in Tetrazine Ligand-Bridged Complexes}, volume = 42, year = 2003 }