Bis(cyclooctadiene)nickel(0)

Bis(cyclooctadiene)nickel(0)

Names
Other names nickel biscod, Ni(COD)2
Identifiers
CAS Number	1295-35-8^Y
3D model (JSmol)	Interactive image
ChemSpider	17215769^Y
ECHA InfoCard	100.013.702
EC Number	215-072-0
PubChem CID	6433264
RTECS number	QR6135000
UN number	1325
CompTox Dashboard (EPA)	DTXSID2024614
InChI InChI=1S/2C8H8.Ni/c2*1-2-4-6-8-7-5-3-1;/h2*1-2,7-8H2;^Y Key: AYHVBQBQROAZHP-UHFFFAOYSA-N^Y InChI=1/2C8H8.Ni/c2*1-2-4-6-8-7-5-3-1;/h2*1-2,7-8H2; Key: AYHVBQBQROAZHP-UHFFFAOYAH
SMILES C1CC=CCCC=C1.C1CC=CCCC=C1.[Ni]
Properties
Chemical formula	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:
Pictograms
Signal word	Danger
Hazard statements	H228, H317, H334, H350, H351
Precautionary statements	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). N verify (what is ^YN ?) Infobox references

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]

Preparation and properties

The 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

The 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

1. Wilke, G. (1988). "Contributions to Organo-Nickel Chemistry". Angewandte Chemie International Edition. 27 (1): 185–206. doi:10.1002/anie.198801851.
2. 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.
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.
4. 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.
5. 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.
6. "Ni(COD)2 60+ Years – Still an Effective Source of Ni(0) in Organometallic Chemistry". Strem Chemical.
7. 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(OR^F)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.
8. 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.