Tungsten hexacarbonyl
Encyclopedia
Tungsten hexacarbonyl is the chemical compound with the formula W(CO)6. This complex gave rise to the first example of a dihydrogen complex.
This colorless compound, like its chromium and molybdenum
analogs, is noteworthy as a volatile, air-stable derivative of tungsten
in its zero oxidation state.
of WCl6
under a pressure of carbon monoxide
. It would be rare to prepare this inexpensive compound in the laboratory because the apparatus is expensive and the compound can be purchased cheaply. The compound is relatively air-stable. It is sparingly soluble in nonpolar organic solvents. Tungsten carbonyl is widely used in electron beam-induced deposition technique - it is easily vaporized and decomposed by the electron beam providing a convenient source of tungsten atoms.
W(CO)6 adopts an octahedral geometry consisting of six rod-like CO ligand
s radiating from the central W atom with dipole moment 0 D
.
One derivative is the dihydrogen complex W(CO)3[P(C6H11)3]2(H2) reported in 1982 by Kubas.
Three of these CO ligands can be displaced by acetonitrile.
W(CO)6 has been used to desulfurize organosulfur compounds and as a precursor to catalysts for alkene metathesis.
This colorless compound, like its chromium and molybdenum
Molybdenum hexacarbonyl
Molybdenum hexacarbonyl is the chemical compound with the formula Mo6. This colorless solid, like its chromium and tungsten analogues, is noteworthy as a volatile, air-stable derivative of a metal in its zero oxidation state.-Structure and properties:Mo6 adopts an octahedral geometry consisting...
analogs, is noteworthy as a volatile, air-stable derivative of tungsten
Tungsten
Tungsten , also known as wolfram , is a chemical element with the chemical symbol W and atomic number 74.A hard, rare metal under standard conditions when uncombined, tungsten is found naturally on Earth only in chemical compounds. It was identified as a new element in 1781, and first isolated as...
in its zero oxidation state.
Preparation, properties, and structure
W(CO)6 is prepared by the reductionRedox
Redox reactions describe all chemical reactions in which atoms have their oxidation state changed....
of WCl6
Tungsten hexachloride
Tungsten hexachloride is the chemical compound of tungsten and chlorine with the formula WCl6. This dark violet blue species exists as a volatile solid under standard conditions. It is an important starting reagent in the preparation of tungsten compounds. WCl6 is a rare example of a...
under a pressure of carbon monoxide
Carbon monoxide
Carbon monoxide , also called carbonous oxide, is a colorless, odorless, and tasteless gas that is slightly lighter than air. It is highly toxic to humans and animals in higher quantities, although it is also produced in normal animal metabolism in low quantities, and is thought to have some normal...
. It would be rare to prepare this inexpensive compound in the laboratory because the apparatus is expensive and the compound can be purchased cheaply. The compound is relatively air-stable. It is sparingly soluble in nonpolar organic solvents. Tungsten carbonyl is widely used in electron beam-induced deposition technique - it is easily vaporized and decomposed by the electron beam providing a convenient source of tungsten atoms.
W(CO)6 adopts an octahedral geometry consisting of six rod-like CO ligand
Ligand
In coordination chemistry, a ligand is an ion or molecule that binds to a central metal atom to form a coordination complex. The bonding between metal and ligand generally involves formal donation of one or more of the ligand's electron pairs. The nature of metal-ligand bonding can range from...
s radiating from the central W atom with dipole moment 0 D
Debye
The debye is a CGS unit of electric dipole momentElectric dipole moment is defined as charge times displacement: Historically the debye was defined as the dipole moment resulting from two charges of opposite sign but an equal magnitude of 10-10 statcoulomb10-10 statcoulomb is approximately 0.2083...
.
Reactivity
All reactions of W(CO)6 commence with displacement of some CO ligands in W(CO)6. W(CO)6 behaves similarly to the Mo(CO)6 but tends to form compounds that are kinetically more robust.One derivative is the dihydrogen complex W(CO)3[P(C6H11)3]2(H2) reported in 1982 by Kubas.
Three of these CO ligands can be displaced by acetonitrile.
W(CO)6 has been used to desulfurize organosulfur compounds and as a precursor to catalysts for alkene metathesis.