A tetranuclear organorhenium(I) complex of the 2,3,5,6-tetrafluoro-7,7,8,8-tetracyano-p-quinodimethane radical anion, TCNQF4-.
The radical complex {\{}($μ$4-TCNQF4)[Re(CO)3(bpy)]4{\}}(PF6)3, as prepd. and isolated from the reaction between TCNQF4 and [Re(CO)3(bpy)(MeOH)](PF6), was studied electrochem. and by IR vibrational spectroscopy, UV-Vis-NIR absorption spectroscopy, and by EPR at 9.5, 190 and 285 GHz. The isotropic g factor of 2.0058, the detectable g anisotropy, and the 185,187Re EPR hyperfine coupling of 0.95 mT for four equiv. metal nuclei support predominant, but not exclusive, spin localization at the bridging ligand. Nitrile and metal carbonyl stretching frequencies as well as the typically structured near IR absorption band lend further support to (TCNQF4-)(ReI)4 as the most appropriate oxidn. state formulation. In comparison to the non-radical complex {\{}($μ$4-TCNQ)[Re(CO)3(bpy)]4{\}}(PF6)4 an X-ray structure anal. of {\{}($μ$4-TCNQF4)[Re(CO)3(bpy)]4{\}}(PF6)3 shows a marginally more twisted (ReNCCCNRe)(C6X4)(ReNCCCNRe) configuration and a different up/down arrangement of the [Re(CO)3(bpy)]+ groups. This first isolation, electrochem., structural and spectroscopic characterization of a discrete tetranuclear radical complex of a TCNQ-type ligand suggests a link between the stability of such materials and the rather small structural changes on ligand-based electron transfer. [on SciFinder(R)]
Références
- Titre
- A tetranuclear organorhenium(I) complex of the 2,3,5,6-tetrafluoro-7,7,8,8-tetracyano-p-quinodimethane radical anion, TCNQF4-.
- Type de publication
- Article de revue
- Année de publication
- 2008
- Auteurs
- Maity, Amarendra N., Sarkar Biprajit, Niemeyer Mark, Sieger Monika, Duboc Carole, Zális Stanislav, and Kaim Wolfgang.
- Revue
- Dalt. Trans.
- Pagination
- 5749–5753
- ISSN
- 1477-9226
- Mots-clés
- crystal structure rhenium carbonyl bipyridine fluorotetracyanoquinodimethane tetranuclear complex cyclic voltammetry rhenium carbonyl bipyridine fluorotetracyanoquinodimethane tetranuclear complex electronic structure rhenium carbonyl bipyridine fluorotetracyanoquinodimethane tetranuclear complex optimized geometry rhenium carbonyl bipyridine fluorotetracyanoquinodimethane tetranuclear complex rhenium carbonyl bipyridine fluorotetracyanoquinodimethane tetranuclear complex prepn structure
- DOI
- 10.1039/b807977c
Soumis le 12 avril 2018