%0 Journal Article %1 Ketterle.1999 %A Ketterle, Michael %A Kaim, Wolfgang %A Olabe, Jose A. %A Parise, Alejandro R. %A Fiedler, Jan. %D 1999 %J Inorganica Chimica Acta %K ESR IR UV bipyridine comproportionation const;mixed cyano electrochem iron prepn pyrazine pyridylethene pyrimidyltetrazine pyrimidyltetrazine;iron pyrimidyltetrazine;pyrazine redox redox;electrochem redox;pyridylethene redox;pyrimidyltetrazine valence %N 1-2 %P 66--73 %R 10.1016/S0020-1693(99)00039-0 %T Widely differing stabilities of molecule-bridged cyanodiiron(III,II) species in non-aqueous solvents %V 291 %X The redox systems (NC)5Fe(m-L)Fe(CN)56-/5-/4- with L = pyrazine (1n), 4,4'-bipyridine (2n) or 1,2-bis(4-pyridyl)ethene (3n), and (NC)4Fe(m-bmtz)Fe(CN)45-/4-/3- (4n) with bmtz = 3,6-bis(2-pyrimidyl)-1,2,4,5-tetrazine were studied in MeCN and other aprotic solvents. The comproportionation consts. Kc for the mixed-valent diiron(III, II) intermediates vary from \textless10 for 35- via 106.5 for 15- to 1014.1 for 43-. Intervalence charge transfer band maxima lie between 1270 nm (25-) and 2475 nm (15-). In comparison with previous results from aq. solns., the system 1n in particular shows increased metal-metal interaction. UV-visible and IR spectroelectrochem. suggest a localized/delocalized borderline situation for 15- in MeCN, with only slightly weaker metal-metal coupling than in the related Creutz-Taube ion. The established strong solvent sensitivity of cyanoiron complexes can be exploited in mixed-valence chem. on SciFinder(R)

@article{Ketterle.1999, abstract = {The redox systems [(NC)5Fe(\textgreek{m}-L)Fe(CN)5]6-/5-/4- with L = pyrazine (1n), 4,4'-bipyridine (2n) or 1,2-bis(4-pyridyl)ethene (3n), and [(NC)4Fe(\textgreek{m}-bmtz)Fe(CN)4]5-/4-/3- (4n) with bmtz = 3,6-bis(2-pyrimidyl)-1,2,4,5-tetrazine were studied in MeCN and other aprotic solvents. The comproportionation consts. Kc for the mixed-valent diiron(III, II) intermediates vary from {\textless}10 for 35- via 106.5 for 15- to 1014.1 for 43-. Intervalence charge transfer band maxima lie between 1270 nm (25-) and 2475 nm (15-). In comparison with previous results from aq. solns., the system 1n in particular shows increased metal-metal interaction. UV-visible and IR spectroelectrochem. suggest a localized/delocalized borderline situation for 15- in MeCN, with only slightly weaker metal-metal coupling than in the related Creutz-Taube ion. The established strong solvent sensitivity of cyanoiron complexes can be exploited in mixed-valence chem. [on SciFinder(R)]}, added-at = {2022-06-15T11:26:56.000+0200}, author = {Ketterle, Michael and Kaim, Wolfgang and Olabe, Jose A. and Parise, Alejandro R. and Fiedler, Jan.}, biburl = {https://puma.ub.uni-stuttgart.de/bibtex/2c465ecb2e796de0eae02a03cd2563bba/huebleriac}, doi = {10.1016/S0020-1693(99)00039-0}, interhash = {1c0d89a65c0c19c8fb69eb8a641860fd}, intrahash = {c465ecb2e796de0eae02a03cd2563bba}, issn = {0020-1693}, journal = {Inorganica Chimica Acta}, keywords = {ESR IR UV bipyridine comproportionation const;mixed cyano electrochem iron prepn pyrazine pyridylethene pyrimidyltetrazine pyrimidyltetrazine;iron pyrimidyltetrazine;pyrazine redox redox;electrochem redox;pyridylethene redox;pyrimidyltetrazine valence}, number = {1-2}, pages = {66--73}, timestamp = {2022-06-15T09:26:56.000+0200}, title = {Widely differing stabilities of molecule-bridged cyanodiiron(III,II) species in non-aqueous solvents}, volume = 291, year = 1999 }