User:Praseodymium-141/Protactinocene
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| Names | |
|---|---|
| IUPAC name
Bis(η8-cyclooctatetraenyl)protactinium(IV)
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| Other names
Protactinium cyclooctatetraenide
Pa(COT)2 | |
| Identifiers | |
3D model (JSmol)
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| Properties | |
| C16H16Pa | |
| Molar mass | 439.340 g·mol−1 |
| Appearance | yellow-ish crystals |
| insoluble, does not react with water | |
| Solubility in chlorocarbons | sparingly soluble (ca. 0.5 g/L) |
| Hazards | |
| Occupational safety and health (OHS/OSH): | |
Main hazards
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radiation hazard, pyrophoric |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Protactinocene, Pa(C8H8)2, is an organoprotactinium compound composed of a protactinium atom sandwiched between two cyclooctatetraenide (COT2-) rings. As a solid it has a yellowish colour.[1]
It was one of the first organoprotactinium compounds to be synthesised, and is a member of the actinocene family of actinide-based metallocenes.[1] It was synthesized in 1974.[2]
Structure
[edit]Protactinocene assumes a monoclinic crystal structure (P21/n space group) which is isomorphous to uranocene and thorocene.[3]
Bonding
[edit]The protactinium-cyclooctatetraenyl bonding, like other actinide bonds, has been of interest for multiple theoretical studies.[4] Computational chemistry methods indicate bonding with a large covalent character resulting mainly from the mixing of protactinium 6d orbitals with ligand π-orbitals, with a smaller interaction involving the protctinium 5f and ligand π-orbitals.[4] The covalent component is characterised by donation of electron density to the protactinium.
References
[edit]- ^ a b Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. pp. 1278–1280. ISBN 9780750633659.
- ^ Goffart, J.; Fuger, J.; Brown, D.; Duyckaerts, G. (1974-05-01). "On the cyclooctatetraenyl compounds of actinide elements part II. Bis-(cyclooctatetraenyl) protactinium(IV)". Inorganic and Nuclear Chemistry Letters. 10 (5): 413–419. doi:10.1016/0020-1650(74)80119-4. ISSN 0020-1650.
- ^ Ridder, D. J. A. De; Rebizant, J.; Apostolidis, C.; Kanellakopulos, B.; Dornberger, E. (1996). "Bis(cyclooctatetraenyl)neptunium(IV)". Acta Crystallographica Section C. 52 (3): 597–600. doi:10.1107/S0108270195013047. ISSN 1600-5759.
- ^ a b Kerridge, Andrew (2014). "f-Orbital covalency in the actinocenes (An = Th–Cm): multiconfigurational studies and topological analysis" (PDF). RSC Advances. 4 (24): 12078–12086. Bibcode:2014RSCAd...412078K. doi:10.1039/C3RA47088A.
Category:Protactinium compounds Category:Organoactinide compounds Category:Metallocenes