Two New Terpyridine Dimanganese Complexes: A Manganese(III,III) Complex with a Single Unsupported Oxo Bridge and a Manganese(III,IV) Complex with a Dioxo Bridge. Synthesis, Structure, and Redox Properties.
Two new terpyridine dimanganese oxo complexes [Mn2III,IV($μ$-O)2(terpy)2(CF3CO2)2]+ (3) and [Mn2III,III($μ$-O)(terpy)2(CF3CO2)4] (4) (terpy = 2,2':6,2''-terpyridine) were synthesized and their x-ray structures detd. In contrast to the corresponding mixed-valent aqua complex [MnIII2,IV($μ$-O)2(terpy)2(H2O)2]3+ (1), the two Mn atoms in 3 are not crystallog. equiv. The neutral binuclear monooxo Mn(III,III) complex 4 exhibits two crystallog. forms having cis and trans configurations. In the cis complex, the two CF3CO2- ligands on each Mn adopt a cis geometry to each other with one CF3CO2- is trans to the O of the oxo bridge. In the trans complex, the two coordinated CF3CO2- ligands have a trans geometry to each other and both are cis to the oxo bridge at each Mn. The electrochem. behavior of 3 in org. medium (MeCN) shows that this complex could be oxidized into its corresponding stable Mn(IV,IV) species while its reduced form Mn(III,III) is very unstable and leads by a disproportionation process to Mn(II) and Mn(IV) complexes. Complex 4 is only stable in the solid state, and it disproportionates spontaneously in MeCN soln. into the mixed-valent complex 3 and mononuclear [MnII(terpy)2]2+ (2), thereby preventing the observation of its electrochem. behavior. [on SciFinder(R)]
Références
- Titre
- Two New Terpyridine Dimanganese Complexes: A Manganese(III,III) Complex with a Single Unsupported Oxo Bridge and a Manganese(III,IV) Complex with a Dioxo Bridge. Synthesis, Structure, and Redox Properties.
- Type de publication
- Article de revue
- Année de publication
- 2002
- Auteurs
- Baffert, Carole, Collomb Marie-Noelle, Deronzier Alain, Pécaut Jacques, Limburg Julian, Crabtree Robert H., and Brudvig Gary W.
- Revue
- Inorg. Chem.
- Volume
- 41
- Pagination
- 1404–1411
- ISSN
- 0020-1669
- Mots-clés
- crystal structure dimanganese oxo terpyridine trifluoroacetato disproportionation manganese oxo terpyridine trifluoroacetato electrochem manganese oxo bridged terpyridine trifluoroacetato manganese oxo bridged terpyridine trifluoroacetato prepn mixed valent manganese oxo terpyridine trifluoroacetato
Soumis le 15 juin 2018