LEBLANC, JC and MOISE, C and VOLPATO, F and BRUNNER, H and GEHART, G and WACHTER, J and NUBER, B (1995) COMPARATIVE-STUDIES IN THE CP(2)M(ETA(2)-S-2)H SERIES (CP=T-BUC(5)H(4), C(5)ME(4)ET, M=NB, TA) ON THE REACTIVITY OF HYDRIDE AND DISULFIDE LIGANDS. JOURNAL OF ORGANOMETALLIC CHEMISTRY, 485 (1-2). pp. 237-242. ISSN 0022-328X,
Full text not available from this repository.Abstract
Reactions of Cp'Ta-2(S-2)H (1; Cp' = t-BuC(5)H(4)) and Cp(2)(x)Nb(S-2)H (2; Cp(x) = C(5)Me(4)Et) with S-8, I-2, and CH3I are investigated. Sulfur insertion into the M-H bond of 1 results in the formation of Cp'3Ta3S12 and Cp'4Ta4S13, where structures are known by analogy, and Cp'6Ta8S17, which is characterised spectroscopically. Complex 2 gives in the analogous reaction Cp(3)(x)Nb(3)S(12) as the only product. This compound desulfurises in boiling decane to give Cp(3)(x)Nb(3)S(7) (8). An X-ray diffraction analysis of 8 revealed an unusual M(3)S(7) core containing four monosulfide and one trisulfide ligand. The polysulfide ligand is arranged in such a way that its inner sulfur atom is at the top of the molecule in a noncoordinating fashion. Whereas reaction of 1 or 2 with I-2 gives spectroscopically characterised Cp'Ta-2(S-2)I and Cp(2)(x)Nb(S-2)I by an H/I exchange, only the reaction of 1 with CH3I leads to well defined products. At 0 degrees C [Cp'Ta-2(S2CH3)H]I is formed as an intermediate product which converts into Cp'Ta-2(=S)I at higher temperatures. The attack of CH3I at the disulfide ligand gives rise to the formation of a chiral sulfur site as inferred from H-1 NMR data.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | POLYSULFIDE COMPLEXES; CRYSTAL-STRUCTURES; CHEMISTRY; SULFUR; NIOBIUM; MOLYBDENUM; BOND; METALLOCENES; HYDRIDE LIGAND; DISULFIDE LIGAND; REACTIVITY; X-RAY STRUCTURE |
| Depositing User: | Dr. Gernot Deinzer |
| Last Modified: | 19 Oct 2022 08:38 |
| URI: | https://pred.uni-regensburg.de/id/eprint/52796 |
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