Bis (cycloocta-1,5-diene) nickel

Structural formula
General
Surname	Bis (cycloocta-1,5-diene) nickel
other names	Bis [(1,2,5,6-η) -1,5-cyclooctadiene] nickel (0); Nickel (COD) 2 ; Ni (COD) 2 ; (1Z, 5Z) -1,5-cyclooctadiene-nickel (2: 1); Bis (1,5-cyclooctadiene) nickel (0); 1,2,5,6-cyclooctanetetraylidene nickel (2: 1);
Molecular formula	C 16 H 24 Ni
Brief description	dark yellow solid
External identifiers / databases
EC number	215-072-0
ECHA InfoCard	100.013.702
PubChem	6433264
ChemSpider	17215769
Wikidata	Q2054690
properties
Molar mass	275.06 g · mol -1
Physical state	firmly
Melting point	60 ° C (decomposition)
solubility	soluble in benzene, toluene, tetrahydrofuran, ether, dimethylformamide, hexamethylphosphoramide and N -methylpyrrolidinone; practically insoluble in water;
safety instructions
H and P phrases	H: 228-334-351
	P: 210-261-281-342 + 311
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Bis (cycloocta-1,5-diene) nickel is an organometallic compound with the constitutional formula [(C ₈ H ₁₂ ) ₂ Ni]. The light-sensitive, yellow nickel (0) complex was first synthesized by Günther Wilke . The complex is widely used in organic synthesis and as a catalyst for organic reactions. The cycloolefin ligands can easily be replaced by other ligands such as phosphines , isonitriles or other olefins .

Manufacturing

Bis (cycloocta-1,5-diene) nickel is synthesized by reducing nickel compounds with organometallic compounds such as triethylaluminum (AlEt ₃ ) or diisobutylaluminum hydride (DIBAH) in the presence of excess 1,5-cyclooctadiene (COD).

A typical production is carried out by the reduction of anhydrous nickel (II) acetylacetonate with triethylaluminum in the presence of 1,5-cyclooctadiene:

{\ displaystyle \ mathrm {Ni (acac) _ {2} +2 \ COD + 2 \ AlEt_ {3} \ longrightarrow Ni (COD) _ {2} +2 \ AlEt_ {2} acac + C_ {2} H_ { 4} + C_ {2} H_ {6}}}

properties

Physical Properties

Bis (cycloocta-1,5-diene) nickel is moderately soluble in benzene and tetrahydrofuran .

The nickel is tetrahedrally surrounded by the four double bonds. The length of the double bonds is increased by 5 pm compared with the free 1,5-cyclooctadiene. The length of all Ni-C bonds is 212 pm.

Chemical properties

The complex can be converted into other nickel (0) complexes in excess of olefinic ligands. Bis (cycloocta-1,5-diene) nickel reacts with acetylacetone to form cyclooctenyl-nickel acetylacetonate.

application

Bis (cycloocta-1,5-diene) nickel serves as a catalyst for the isomerization and hydrosilylation of unsaturated compounds, as a co-catalyst for the oligomerization / cyclooligomerization or polymerization of alkenes, for the cycloaddition of 1,3-dienes, is used to catalyze the Addition of allylphenyl sulfide to alkynes and other reactions are used.

Coupling reactions of aryl halides such as phenyl bromide with bis (cycloocta-1,5-diene) nickel in the presence of 2,2'-bipyridine or triphenylphosphine as an auxiliary ligand lead to the corresponding biaryl as a coupling product (ArX = aryl halide; X = halide; Ar ₂ = biaryl; NiX ₂ = nickel halide).

{\ displaystyle \ mathrm {Ni (COD) _ {2} +2 \ ArX \ longrightarrow NiX_ {2} + Ar_ {2} +2 \ COD}}

Bis (cycloocta-1,5-diene) nickel has a catalytic effect in the synthesis of ring compounds from 1,3-butadiene. The complex loses the 1,5-cyclooctadiene ligands, which are replaced by 1,3-butadiene during the reaction. The resulting nickel is also known as "bare" nickel. Ring closure reactions to 1,5-cyclooctadiene and 1,5,9-cyclododecatriene are observed at temperatures as low as −60 to −40 ° C.

The compound also serves as a starting material for the production of other nickel complexes, since the cyclooctadiene ligands can easily be substituted.

Individual evidence

↑ ^a ^b ^c ^d ^e data sheet bis (1,5-cyclooctadiene) nickel (0) from Sigma-Aldrich , accessed on December 26, 2016 ( PDF ).
↑ ^a ^b ^c data sheet bis (1,5-cyclooctadiene) nickel (0) at AlfaAesar, accessed on December 26, 2016 ( PDF )(JavaScript required) .
↑ ^a ^b ^c Borislav Bogdanović , Michael Kröner, Günther Wilke: Transition Metal Complexes, I. Olefin Complexes of Nickel (0). In: Justus Liebig's Annals of Chemistry. 699, 1966, pp. 1-23, doi : 10.1002 / jlac.19666990102 .
↑ Damian J. Krysan, Peter B. Mackenzie: A new, convenient preparation of bis (1,5-cyclooctadiene) nickel (0). In: The Journal of Organic Chemistry. 55, 1990, pp. 4229-4230, doi : 10.1021 / jo00300a057 .
↑ ^a ^b R. A. Schunn: bis (1,5-cyclooctadiene) nickel (0) . In: George W. Parshall (Ed.): Inorganic Syntheses . tape 15 . McGraw-Hill Book Company, Inc., 1974, ISBN 0-07-048521-6 , pp. 5-9 (English).
↑ Hinbich Diebks, Hans Dietrich: The crystal structure of bis-cyclooctadiene- (1,5) -nickel (0). In: Journal of Crystallography - Crystalline Materials. 122, 1965, pp. 1-23, doi : 10.1515 / zkri-1965-1-602 .
↑ Takakazu Yamamoto, Shoichiro Wakabayashi, Kohtaro Osakada: Mechanism of CC coupling reactions of aromatic halides, promoted by Ni (COD) 2 in the presence of 2,2′-bipyridine and PPh3, to give biaryls. In: Journal of Organometallic Chemistry. 428, 1992, p. 223, doi : 10.1016 / 0022-328X (92) 83232-7 .
↑ H. Breil, P. Heimbach, M. Kröner, H. Müller, G. Wilke: Synthesis of Cyclododecatrien- (1,5,9). I. Mitt. On the catalytic conversion of olefins. In: The Macromolecular Chemistry. 1963, 69, pp. 18-40, doi : 10.1002 / macp.1963.020690102 .

[Sigma-1] ↑ ^a ^b ^c ^d ^e data sheet bis (1,5-cyclooctadiene) nickel (0) from Sigma-Aldrich , accessed on December 26, 2016 ( PDF ).

[Alfa-2] ta sheet bis (1,5-cyclooctadiene) nickel (0) at AlfaAesar, accessed on December 26, 2016 ( PDF )(JavaScript required) .

[wilke1-3] Borislav Bogdanović , Michael Kröner, Günther Wilke: Transition Metal Complexes, I. Olefin Complexes of Nickel (0). In: Justus Liebig's Annals of Chemistry. 699, 1966, pp. 1-23, doi : 10.1002 / jlac.19666990102 .

[krysan-4] Damian J. Krysan, Peter B. Mackenzie: A new, convenient preparation of bis (1,5-cyclooctadiene) nickel (0). In: The Journal of Organic Chemistry. 55, 1990, pp. 4229-4230, doi : 10.1021 / jo00300a057 .

[IS15-5] R. A. Schunn: bis (1,5-cyclooctadiene) nickel (0) . In: George W. Parshall (Ed.): Inorganic Syntheses . tape 15 . McGraw-Hill Book Company, Inc., 1974, ISBN 0-07-048521-6 , pp. 5-9 (English).

[diebks-6] Hinbich Diebks, Hans Dietrich: The crystal structure of bis-cyclooctadiene- (1,5) -nickel (0). In: Journal of Crystallography - Crystalline Materials. 122, 1965, pp. 1-23, doi : 10.1515 / zkri-1965-1-602 .

[yamamoto-7] Takakazu Yamamoto, Shoichiro Wakabayashi, Kohtaro Osakada: Mechanism of CC coupling reactions of aromatic halides, promoted by Ni (COD) 2 in the presence of 2,2′-bipyridine and PPh3, to give biaryls. In: Journal of Organometallic Chemistry. 428, 1992, p. 223, doi : 10.1016 / 0022-328X (92) 83232-7 .

[wilke2-8] H. Breil, P. Heimbach, M. Kröner, H. Müller, G. Wilke: Synthesis of Cyclododecatrien- (1,5,9). I. Mitt. On the catalytic conversion of olefins. In: The Macromolecular Chemistry. 1963, 69, pp. 18-40, doi : 10.1002 / macp.1963.020690102 .