Spectral properties and reactivity of the binuclear complex ion μ-(p-benzoquinonediimine)bis[pentacyanoferrate(II)]
A sodium salt containing the binuclear complex anion μ-(p-benzoquinonediimine) bis(pentacyanoferrate(II)], [(NC)5FeHNC6H4NHFe(CN)5]6- [first described by Herington(3)) has been isolated as a solid from an oxygenated solution ofp-phenylenediamine and sodium amminepentacyanoferrate(II) in a 1∶2 molar...
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| Autores principales: | , , , |
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| Formato: | Articulo |
| Lenguaje: | Inglés |
| Publicado: |
1991
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| Materias: | |
| Acceso en línea: | http://sedici.unlp.edu.ar/handle/10915/140227 |
| Aporte de: |
| Sumario: | A sodium salt containing the binuclear complex anion μ-(p-benzoquinonediimine) bis(pentacyanoferrate(II)], [(NC)5FeHNC6H4NHFe(CN)5]6- [first described by Herington(3)) has been isolated as a solid from an oxygenated solution ofp-phenylenediamine and sodium amminepentacyanoferrate(II) in a 1∶2 molar ratio. The i.r. and u.v.-vis. spectra point to a quinonediimine structure for the bridging ligand. In aqueous solution this ion dissociates into aquopentacyanoferrate(II) andp-benzoquinonediiminepentacyanoferrate(II), with kobs=1.1×10−2s−1. The formation of the mononuclear pentacyanoferrate(II) complex of protonatedp-benzoquinonediimine is favoured at pH≤8. The pKa value for the coordinated diimine isca. two orders of magnitude higher than that for the free ligand, thus indicating thatp-benzoquinonediimine is stabilized by coordination to the [Fe(CN)5]3- moiety, though to a lesser extent than in rutheniumammine analogues. |
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