Brandl, Martin and Brunner, Henri and Wachter, Joachim and Zabel, Manfred (2002) Rotational versus migration isomerism in [{(tBuC(5)H(4))(2)NbH(mu(3)-Te)(mu(4)-Te)Fe-2(CO)(6)}center dot Cr(CO)(5)], a sterically crowded polymetallic telluride complex. ORGANOMETALLICS, 21 (14). pp. 3069-3072. ISSN 0276-7333
Full text not available from this repository.Abstract
The reaction of [Cp'Nb-2(Te-2)H] (1) (Cp' = tBuC(5)H(4)) with [Fe-2(CO)(9)] gives [{Cp'2NbH(Te)(2)}Fe-2(CO)(6)](2). Compound 2 reacts with [Cr(CO)(5)THF] to give [{Cp'2NbH(Te)(2)Fe-2(CO)(6)}Cr-.(CO)(5)] (3) in nearly quantitative yield. The crystal structure of 3 reveals that the Fe-2(CO)(6) unit in this complex (and consequently in 2) is inserted in a perpendicular manner into the original NbTe2 moiety of 1, while the incoming Cr(CO)(5) fragment is attached at the central Te atom and in vicinity (vic) to the Nb-H moiety. H-1 NMR investigations of solutions of 3 at -80 degreesC show that only the sterically crowded vic-3 has been separated by recrystallization. At -60 degreesC a rapid exchange is observed for the ring protons, which may be explained by rotation of the Cp' rings around the Cp'-Nb axes. Above 0 degreesC an additional Set Of C5H4, tBu, and NbH resonances appears, which may be assigned to migration of the Cr(CO)(5) fragment from the central to the lateral Te atom. The resulting opp-3 is in a 55:45 equilibrium with vic-3 at 20 degreesC.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | COORDINATION CHEMISTRY; METALLOCENE COMPLEXES; REACTIVITY; DERIVATIVES; FRAGMENTS; CHALCOGEN; CLUSTERS; CARBONYL; LIGANDS; SE; |
| Subjects: | 500 Science > 540 Chemistry & allied sciences |
| Divisions: | Chemistry and Pharmacy > Institut für Anorganische Chemie |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 12 Oct 2021 12:53 |
| Last Modified: | 12 Oct 2021 12:53 |
| URI: | https://pred.uni-regensburg.de/id/eprint/40089 |
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