Bis(cyclooctadiene)nickel(0) is the
organonickel compound
Organonickel chemistry is a branch of organometallic chemistry that deals with organic compounds featuring nickel-carbon bonds. They are used as a catalyst, as a building block in organic chemistry and in chemical vapor deposition. Organonickel com ...
with the formula Ni(C
8H
12)
2, also written Ni(cod)
2. It is a diamagnetic
coordination complex
A coordination complex consists of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of bound molecules or ions, that are in turn known as ''ligands'' or complexing agents. Many ...
featuring tetrahedral nickel(0) bound to the alkene groups in two
1,5-cyclooctadiene
Cycloocta-1,5-diene is a cyclic hydrocarbon with the chemical formula , specifically .
There are three configurational isomers with this structure, that differ by the arrangement of the four C–C single bonds adjacent to the double bonds. Each ...
ligand
In coordination chemistry, a ligand is an ion or molecule (functional group) that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's electr ...
s. This highly air-sensitive yellow solid is a common source of Ni(0) in chemical synthesis.
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 acacAlEt
2 + C
2H
6 + C
2H
4
Ni(cod)
2 is moderately soluble in several organic solvents. One or both
1,5-cyclooctadiene
Cycloocta-1,5-diene is a cyclic hydrocarbon with the chemical formula , specifically .
There are three configurational isomers with this structure, that differ by the arrangement of the four C–C single bonds adjacent to the double bonds. Each ...
ligands are readily displaced by phosphines, phosphites,
bipyridine, and
isocyanides. If exposed to air, the solid oxidizes to
nickel(II) oxide
Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow to r ...
. As a result, this compound is generally handled in a
glovebox.
References
{{Nickel compounds
Organonickel compounds
Cyclooctadiene complexes