Kaufmann, Linda and Breunig, Jens-Michael and Vitze, Hannes and Schoedel, Frauke and Nowik, Israel and Pichlmaier, Markus and Bolte, Michael and Lerner, Hans-Wolfram and Winter, Rainer F. and Herber, Rolfe H. and Wagner, Matthias (2009) Electronic communication in oligonuclear ferrocene complexes with anionic four-coordinate boron bridges. DALTON TRANSACTIONS (16). pp. 2940-2950. ISSN 1477-9226, 1477-9234
Full text not available from this repository. (Request a copy)Abstract
The di- and trinuclear ferrocene species Li[Fc-BPh2-Fc] (Li[9]) and Li-2[Fc-BPh2-fc-BPh2-Fc] (Li-2[10]) have been investigated with regard to their electrochemical properties and the degree of intervalence charge-transfer after partial oxidation. Li[9] shows two distinct one-electron redox waves for its chemically equivalent ferrocenyl substituents in the cyclic voltammogram (E-1/2 = -0.38 V, -0.64 V; vs. FcH/FcH(+)). The corresponding values of Li-2[10] are E-1/2 = -0.45 V (two-electron process) and -1.18 V. All these redox events are reversible at r. t. on the time scale of cyclic voltammetry. X-ray crystallography on the mixed-valent (Fe2FeIII)-Fe-II complex Li(12-c-4)(2)[10] reveals the centroid-centroid distance between the cyclopentadienyl rings of each of the terminal ferrocenyl substituents (3.329 angstrom) to be significantly smaller than in the central 1,1'-ferrocenediyl fragment (3.420 angstrom). This points towards a charge-localized structure (on the time scale of X-ray crystallography) with the central iron atom being in the Fe-III state. Mossbauer spectroscopic measurements on Li(12-c-4)(2)[10] lend further support to this interpretation. Spectroelectrochemical measurements on Li[9] and Li-2[10] in the wavelength range between 300-2800 nm do not show bands interpretable as intervalence charge-transfer absorptions for the mixed-valent states. All data accumulated so far lead to the conclusion that electronic interaction between the individual Fe atoms in Li[9] and Li-2[10] occurs via a through-space pathway and/or is electrostatic in nature.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | RING-OPENING POLYMERIZATION; METAL ATOM MOTION; SUBSTITUTED FERROCENES; HYPERFINE INTERACTIONS; COORDINATION POLYMERS; IRON-ORGANOMETALLICS; CRYSTAL-STRUCTURE; MAIN-CHAIN; ROUTE; CHEMISTRY; |
| Subjects: | 500 Science > 540 Chemistry & allied sciences |
| Divisions: | Chemistry and Pharmacy > Institut für Anorganische Chemie |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 12 Oct 2020 08:09 |
| Last Modified: | 12 Oct 2020 08:09 |
| URI: | https://pred.uni-regensburg.de/id/eprint/29707 |
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