Bis(η-tert-butylcyclopentadienyl)hydridoniobium Ditelluride, a Convenient Reagent for the Synthesis of Polynuclear Metal Telluride Complexes
✍ Scribed by Henri Brunner; Helene Cattey; David Evrard; Marek M. Kubicki; Yves Mugnier; Estelle Vigier; Joachim Wachter; Robert Wanninger; Manfred Zabel
- Book ID
- 101347901
- Publisher
- John Wiley and Sons
- Year
- 2002
- Tongue
- English
- Weight
- 257 KB
- Volume
- 2002
- Category
- Article
- ISSN
- 1434-1948
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✦ Synopsis
Reaction of [CpЈ 2 NbH 3 ] (CpЈ = tBuC 5 H 4 ) with Te powder in THF gives [CpЈ 2 Nb(Te 2 )H] (1) and [CpЈ 6 Nb 4 Te 4 O] (2). The yield of 1 varies between 10 and 81% depending on the degree of oxygen contamination of the reagents. Complexes 1 and 2 react with [Cr(CO) 5 THF] to give [CpЈ 2 Nb-(Te 2 )H•Cr(CO) 5 ] (3) and [CpЈ 6 Nb 4 Te 4 O•2Cr(CO) 5 ] (4), respectively. The crystal structures of 2-4 have been determined. In 3 a Te 2 unit and an H ligand are coordinated to a bent niobocene moiety; the Cr(CO) 5 group is attached to the lateral Te atom. The molecular cores of 2 and 4 are practically identical in that they contain two planar Nb 2 Te 2 rings connected by a nearly linear oxygen bridge. Each of the ''outer'' Nb atoms bears two CpЈ ligands, whereas the ''inner'' Nb atom only has one such ligand. An additional structural feature in 4 is two Cr(CO) 5 groups, attached to one Te bridge of each Nb 2 Te 2 ring. Thermolysis of 3 leads to the formation of diamagnetic [CpЈ 4 Nb 2 Te 2 ] (5), which also contains a planar Nb 2 Te 2 core. The relatively long transannular Nb-Nb distance (3.647 A ˚) is consistent, according to DFT calculations, with a through-space Nb-Nb coupling. Complex 5 reacts