Tris(acetylacetonato)cobalt(III)

Last updated
Tris(acetylacetonato)cobalt(III)
Co(acac)3.png
Names
Other names
Cobalt(III) acetylacetonate, tris(acac) cobalt
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.040.464 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 244-527-6
PubChem CID
  • InChI=1S/3C5H8O2.Co/c3*1-4(6)3-5(2)7;/h3*3,6H,1-2H3;/q;;;+3/p-3/b3*4-3+;
    Key: RHCQEPWEBDOALW-MUCWUPSWSA-K
  • C/C(=C\C(=O)C)/[O-].C/C(=C\C(=O)C)/[O-].C/C(=C\C(=O)C)/[O-].[Co+3]
Properties
C15H21CoO6
Molar mass 356.260 g·mol−1
Appearancegreen solid
Density 1.41 g/cm3
Melting point 213 °C (415 °F; 486 K)
Hazards
GHS labelling:
GHS-pictogram-exclam.svg GHS-pictogram-silhouette.svg
Danger
H302, H317, H334
P261, P264, P270, P272, P280, P285, P301+P312, P302+P352, P304+P341, P321, P330, P333+P313, P342+P311, P363, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Tris(acetylacetonato)cobalt(III) is the coordination complex with the formula Co(C5H7O2)3. Often abbreviated Co(acac)3, it is a green, diamagnetic solid that is soluble in organic solvents, but not in water. Owing to its solubility in organic solvents, tris(acetylacetonato)cobalt(III) is used to produce homogeneous catalysts by reduction. [1]

Contents

Structure

The structure of the complex has been confirmed by X-ray crystallography. The three acac ligands bind in a bidentate fashion to cobalt, defining an octahedral complex. [2] The solid is isomorphous with tris(acetylacetonato)iron(III), tris(acetylacetonato)manganese(III), and tris(acetylacetonato)aluminium. With D3-symmetry, these complexes are chiral and often can be resolved into the individual enantiomers.

Synthesis and reactions

Tris(acetylacetonato)cobalt(III) is prepared by the reaction of cobalt(II) carbonate and acetylacetone in the presence of hydrogen peroxide: [3]

2 CoCO3 + 6 CH3COCH2COCH3 + H2O2 → 2 Co(O2C3Me2H)3 + 2 CO2 + 4 H2O

One distinctive aspect of Co(acac)3 is its susceptibility toward electrophilic aromatic substitution, by which protons on the central carbon are replaced with diverse electrophiles (Me = methyl): [4]

Co(O2C3Me2H)3 + 3 NO2+ → Co(O2C3Me2NO2)3 + 3 H+

Related Research Articles

<span class="mw-page-title-main">Rhodium(III) chloride</span> Chemical compound

Rhodium(III) chloride refers to inorganic compounds with the formula RhCl3(H2O)n, where n varies from 0 to 3. These are diamagnetic solids featuring octahedral Rh(III) centres. Depending on the value of n, the material is either a dense brown solid or a soluble reddish salt. The soluble trihydrated (n = 3) salt is widely used to prepare compounds used in homogeneous catalysis, notably for the industrial production of acetic acid and hydroformylation.

<span class="mw-page-title-main">Trimethylolpropane phosphite</span> Chemical compound

Trimethylolpropane phosphite, C2H5C(CH2O)3P, is a phosphite ester used as a ligand in organometallic chemistry. Trimethylolpropane phosphite is sometimes abbreviated to EtCage. It is a white solid that is soluble in organic solvents. It is also highly toxic.

<span class="mw-page-title-main">Chromium(III) acetylacetonate</span> Chemical compound

Chromium(III) acetylacetonate is the coordination compound with the formula Cr(C5H7O2)3, sometimes designated as Cr(acac)3. This purplish coordination complex is used in NMR spectroscopy as a relaxation agent because of its solubility in nonpolar organic solvents and its paramagnetism.

<span class="mw-page-title-main">Cobalt(II) carbonate</span> Chemical compound

Cobalt(II) carbonate is the inorganic compound with the formula CoCO3. This reddish paramagnetic solid is an intermediate in the hydrometallurgical purification of cobalt from its ores. It is an inorganic pigment, and a precursor to catalysts. Cobalt(II) carbonate also occurs as the rare red/pink mineral spherocobaltite.

<span class="mw-page-title-main">Bis(cyclooctadiene)nickel(0)</span> Chemical compound

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.

<span class="mw-page-title-main">Nickel(II) bis(acetylacetonate)</span> Coordination complex

Nickel(II) bis(acetylacetonate) is a coordination complex with the formula [Ni(acac)2]3, where acac is the anion C5H7O2 derived from deprotonation of acetylacetone. It is a dark green paramagnetic solid that is soluble in organic solvents such as toluene. It reacts with water to give the blue-green diaquo complex Ni(acac)2(H2O)2.

<span class="mw-page-title-main">Ruthenium(III) acetylacetonate</span> Chemical compound

Ruthenium(III) acetylacetonate is a coordination complex with the formula Ru(O2C5H7)3. O2C5H7 is the ligand called acetylacetonate. This compound exists as a dark violet solid that is soluble in most organic solvents. It is used as a precursor to other compounds of ruthenium.

<span class="mw-page-title-main">Tris(acetylacetonato)iron(III)</span> Chemical compound

Tris(acetylacetonato) iron(III), often abbreviated Fe(acac)3, is a ferric coordination complex featuring acetylacetonate (acac) ligands, making it one of a family of metal acetylacetonates. It is a red air-stable solid that dissolves in nonpolar organic solvents.

Metal acetylacetonates are coordination complexes derived from the acetylacetonate anion (CH
3
COCHCOCH
3
) and metal ions, usually transition metals. The bidentate ligand acetylacetonate is often abbreviated acac. Typically both oxygen atoms bind to the metal to form a six-membered chelate ring. The simplest complexes have the formula M(acac)3 and M(acac)2. Mixed-ligand complexes, e.g. VO(acac)2, are also numerous. Variations of acetylacetonate have also been developed with myriad substituents in place of methyl (RCOCHCOR). Many such complexes are soluble in organic solvents, in contrast to the related metal halides. Because of these properties, acac complexes are sometimes used as catalyst precursors and reagents. Applications include their use as NMR "shift reagents" and as catalysts for organic synthesis, and precursors to industrial hydroformylation catalysts. C
5
H
7
O
2
in some cases also binds to metals through the central carbon atom; this bonding mode is more common for the third-row transition metals such as platinum(II) and iridium(III).

<span class="mw-page-title-main">Vanadyl acetylacetonate</span> Chemical compound

Vanadyl acetylacetonate is the chemical compound with the formula VO(acac)2, where acac is the conjugate base of acetylacetone. It is a blue-green solid that dissolves in polar organic solvents. The coordination complex consists of the vanadyl group, VO2+, bound to two acac ligands via the two oxygen atoms on each. Like other charge-neutral acetylacetonate complexes, it is not soluble in water.

<span class="mw-page-title-main">Metal bis(trimethylsilyl)amides</span>

Metal bis(trimethylsilyl)amides are coordination complexes composed of a cationic metal M with anionic bis(trimethylsilyl)amide ligands (the N 2 monovalent anion, or −N 2 monovalent group, and are part of a broader category of metal amides.

<span class="mw-page-title-main">Dysprosium acetylacetonate</span> Chemical compound

Dysprosium acetylacetonate is a chemical compound of dysprosium with formula Dy(C5H7O2)3(H2O)n.

<span class="mw-page-title-main">Iridium acetylacetonate</span> Chemical compound

Iridium acetylacetonate is the iridium coordination complex with the formula Ir(O2C5H7)3, which is sometimes known as Ir(acac)3. The molecule has D3-symmetry. It is a yellow-orange solid that is soluble in organic solvents.

The Mukaiyama hydration is an organic reaction involving formal addition of an equivalent of water across an olefin by the action of catalytic bis(acetylacetonato)cobalt(II) complex, phenylsilane and atmospheric oxygen to produce an alcohol with Markovnikov selectivity.

<span class="mw-page-title-main">Rhodium acetylacetonate</span> Chemical compound

Rhodium acetylacetonate is the coordination complex with the formula Rh(C5H7O2)3, which is sometimes known as Rh(acac)3. The molecule has D3-symmetry. It is a yellow-orange solid that is soluble in organic solvents.

<span class="mw-page-title-main">Zirconium acetylacetonate</span> Chemical compound

Zirconium acetylacetonate is the coordination complex with the formula Zr(C5H7O2)4. It is a common acetylacetonate of zirconium. It is a white solid that exhibits high solubility in nonpolar organic solvents, but not simple hydrocarbons.

<span class="mw-page-title-main">Vanadium(III) acetylacetonate</span> Chemical compound

Vanadium(III) acetylacetonate is the coordination compound with the formula V(C5H7O2)3, sometimes designated as V(acac)3. It is an orange-brown solid that is soluble in organic solvents.

<span class="mw-page-title-main">Tris(acetylacetonato)titanium(III)</span> Chemical compound

Tris(acetylacetonato)titanium(III), often abbreviated Ti(acac)3, is a coordination complex of titanium(III) featuring acetylacetonate (acac) ligands, making it one of a family of metal acetylacetonates. It is a blue air-sensitive solid that dissolves in nonpolar organic solvents. The compound is prepared by treating titanium trichloride with acetylacetone in the presence of base. Being paramagnetic, it gives a contact-shifted proton NMR signal at 60 ppm upfield of TMS assigned to the methyl group.

<span class="mw-page-title-main">Zinc acetylacetonate</span> Chemical compound

Zinc acetylacetonate is an acetylacetonate complex of zinc, with the chemical formula of Zn(C5H7O2)2. The compound is in fact a trimer, Zn3(acac)6, in which each Zn ion is coordinated by five oxygen atoms in a distorted trigonal bipyramidal structure.

<span class="mw-page-title-main">Praseodymium acetylacetonate</span> Chemical compound

Praseodymium acetylacetonate is a coordination complex with the formula Pr(C3H7O2)3. This purported anhydrous acetylacetonate complex is widely discussed but only the dihydrate Pr(C3H7O2)3(H2O)2 has been characterized by X-ray crystallography.

References

  1. Mayo, Peter D.; Tam, William (2002). "Tris(acetoacetonyl)cobalt". Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rn00084. ISBN   0-471-93623-5.
  2. Arslan, Evrim; Lalancette, Roger A.; Bernal, Ivan (2017). "An Historic and Scientific Study of the Properties of Metal(III) Tris-acetylacetonates". Structural Chemistry. 28: 201–212. doi:10.1007/s11224-016-0864-0. S2CID   99668641.
  3. Bryant, Burl E.; Fernelius, W. Conard (1957). Cobalt(III) Acetylacetonate. Inorganic Syntheses. Vol. 5. pp. 188–189. doi:10.1002/9780470132364.ch53. ISBN   978-0-470-13236-4.
  4. Shalhoub, George M. (1980). "Co(acac)3 Synthesis, Reactions, and Spectra: An Experiment for General Chemistry". Journal of Chemical Education. 57 (7): 525. Bibcode:1980JChEd..57..525S. doi:10.1021/ed057p525.