Cyclopentadienylthallium, also known as thallium cyclopentadienide, is an organothallium compound with formula C5H5Tl. This light yellow solid is insoluble in most organic solvents, but sublimes readily. It is used as a precursor to transition metal and main group cyclopentadienyl complexes, as well as organic cyclopentadiene derivatives.[1]
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| Names | |
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| IUPAC name
Thallium(I) cyclopentadienide
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| Other names
Thallium cyclopentadienide
(η5-Cyclopentadienyl)thallium | |
| Identifiers | |
3D model (JSmol)
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| ChemSpider | |
| ECHA InfoCard | 100.047.466 |
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PubChem CID
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| Properties | |
| C5H5Tl | |
| Molar mass | 269.48 g·mol−1 |
| Appearance | Light yellow solid |
| Melting point | 300 °C (572 °F; 573 K) |
| Insoluble | |
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Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Preparation and structure
editCyclopentadienylthallium is prepared by the reaction of thallium(I) sulfate, sodium hydroxide, and cyclopentadiene:[2]
- Tl2SO4 + 2 NaOH → 2 TlOH + Na2SO4
- TlOH + C5H6 → TlC5H5 + H2O
The compound adopts a polymeric structure, consisting of infinite chains of bent metallocenes. The Tl---Tl---Tl angles are 130°.[3] Upon sublimation, the polymer cracks into monomers of C5v symmetry.
Applications
editCompared to other cyclopentadienyl (Cp) transfer reagents, such as cyclopentadienyl sodium, CpMgBr and Cp2Mg, cyclopentadienylthallium is less air sensitive. It is also much less of a reducing agent.
References
edit- ^ C. Elschenbroich (2006). Organometallics. Wiley-VCH, Weinheim. p. 130. ISBN 3-527-29390-6.
- ^ A.J. Nielson; C.E.F. Rickard; J.M. Smith (2007). "Cyclopentadienylthallium (Thallium Cyclopentadienide)". Inorganic Syntheses. Vol. 24. pp. 97–99. doi:10.1002/9780470132555.ch31. ISBN 9780470132555.
- ^ Falk Olbrich, Ulrich Behrens "Crystal structure of catena-cyclopentadienylthallium, [Tl(C5H5)]" Zeitschrift für Kristallographie - New Crystal Structures 1997, 212, 47-47.