Bis(cyclooctadiene)nickel(0) is the organonickel compound with the formula Ni(C8H12)2, also written Ni(cod)2. It is a diamagnetic coordination complex featuring tetrahedral nickel(0) bound to the alkene groups in two 1,5-cyclooctadiene ligands. This highly air-sensitive yellow solid is a common source of Ni(0) in chemical synthesis.[1]
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| Names | |
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| Other names
nickel biscod, Ni(COD)2
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| Identifiers | |
3D model (JSmol)
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| ChemSpider | |
| ECHA InfoCard | 100.013.702 |
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PubChem CID
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| UN number | 1325 |
CompTox Dashboard (EPA)
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| Properties | |
| C16H24Ni | |
| Molar mass | 275.06 g/mol |
| Appearance | Yellow solid |
| Melting point | 60 °C (140 °F; 333 K) (N2, decomposes) |
| Solubility | soluble in benzene, tetrahydrofuran, toluene, diethyl ether, dimethylformamide |
| Hazards | |
| GHS labelling: | |
  
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| Danger | |
| H228, H317, H334, H350, H351 | |
| P201, P202, P210, P240, P241, P261, P272, P280, P281, P285, P302+P352, P304+P341, P308+P313, P321, P333+P313, P342+P311, P363, P370+P378, P405, P501 | |
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 properties
editThe complex is prepared by reduction of anhydrous nickel(II) acetylacetonate in the presence of the diolefin:
- Ni(acac)2 + 2 cod + 2 AlEt3 → Ni(cod)2 + 2 acacAlEt2 + C2H6 + C2H4
Ni(cod)2 is moderately soluble in several organic solvents.[2][3]
If exposed to air, the solid oxidizes in a few minutes to nickel(II) oxide.[4] As a result, this compound is generally handled in a glovebox.[5]
Reactions
editThe reactivity of Ni(cod)2 has been extensively examined. One or both 1,5-cyclooctadiene ligands are readily displaced by phosphines, phosphites, bipyridine, and isocyanides. [6]
Oxidation gives the highly reactive monocation, which can be isolated when using weakly coordinating anions:[7]
- Ni(cod)2 + Ag[Al(OCH(CF3)2)4] → [Ni(cod)2][Al(OCH(CF3)2)4] + Ag
Of its many catalytic reactions,[5] Ni(cod)2 in the presence of phosphine ligands catalyzes the demethoxylation of anisoles by hydrosilanes:[8]
- 2 C6H5OCH3 + [(CH3)2HSi]2O → 2 C6H6 + [(CH3)2(CH3O)Si]2O
References
edit- ^ Wilke, G. (1988). "Contributions to Organo-Nickel Chemistry". Angewandte Chemie International Edition. 27 (1): 185–206. doi:10.1002/anie.198801851.
- ^ Schunn, R. A.; Ittel, S. D.; Cushing, M. A. (1990). "Bis(1,5-Cyclooctadiene)Nickel(0)". Inorganic Syntheses. Inorganic Syntheses. Vol. 28. pp. 94–98. doi:10.1002/9780470132593.ch25. ISBN 978-0-470-13259-3.
- ^ Wender, Paul A.; Smith, Thomas E.; Duong, Hung A.; Louie, Janis; Standley, Eric A.; Tasker, Sarah Z. (2015). "Bis(1,5-cyclooctadiene)nickel(0)". Encyclopedia of Reagents for Organic Synthesis. John Wiley & Sons Ltd: 1–15. doi:10.1002/047084289x.rb118.pub3. ISBN 9780470842898.
- ^ Zhu, Kake; D'Souza, Lawrence; Richards, Ryan M. (September 2005). "Planting of bis(1,5-cyclooctadiene) nickel upon silica to harvest NiO (<5 nm) nanoparticles in a silica matrix". Applied Organometallic Chemistry. 19 (9): 1065–1069. doi:10.1002/aoc.974.
- ^ a b Tasker, Sarah Z.; Standley, Eric A.; Jamison, Timothy F. (2014). "Recent advances in homogeneous nickel catalysis". Nature. 509 (7500): 299–309. Bibcode:2014Natur.509..299T. doi:10.1038/nature13274. PMC 4344729. PMID 24828188.
- ^ "Ni(COD)2 60+ Years – Still an Effective Source of Ni(0) in Organometallic Chemistry". Strem Chemical.
- ^ Schwab, Miriam M.; Himmel, Daniel; Kacprzak, Sylwia; Kratzert, Daniel; Radtke, Valentin; Weis, Philippe; Ray, Kallol; Scheidt, Ernst-Wilhelm; Scherer, Wolfgang; De Bruin, Bas; Weber, Stefan; Krossing, Ingo (2015). "[Ni(cod)2][Al(ORF)4], a Source for Naked Nickel(I) Chemistry". Angewandte Chemie International Edition. 54 (49): 14706–14709. doi:10.1002/anie.201506475. PMC 5531756. PMID 26458726.
- ^ Cornella, Josep; Zarate, Cayetana; Martin, Ruben (2014). "Ni-catalyzed Reductive Cleavage of Methyl 3-Methoxy-2-Naphthoate". Organic Syntheses. 91: 260–272. doi:10.15227/orgsyn.091.0260.