Chromium acetylacetonate is the coordination compound with the formula

Chemical formula

A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....

 Cr(C₅H₇O₂)₃, sometimes designated as Cr(acac)₃. This purplish coordination complex

Complex (chemistry)

In chemistry, a coordination complex or metal complex, is an atom or ion , bonded to a surrounding array of molecules or anions, that are in turn known as ligands or complexing agents...

 is used in NMR spectroscopy

NMR spectroscopy

Nuclear magnetic resonance spectroscopy, most commonly known as NMR spectroscopy, is a research technique that exploits the magnetic properties of certain atomic nuclei to determine physical and chemical properties of atoms or the molecules in which they are contained...

 as a relaxation agent because of its solubility in nonpolar organic solvents and its paramagnetism

Paramagnetism

Paramagnetism is a form of magnetism whereby the paramagnetic material is only attracted when in the presence of an externally applied magnetic field. In contrast with this, diamagnetic materials are repulsive when placed in a magnetic field...

.

Synthesis and structure

The compound is prepared by the reaction of chromium(III) oxide

Chromium(III) oxide

Chromium oxide is the inorganic compound of the formula Cr2O3. It is one of principal oxides of chromium and is used as a pigment. In nature, it occurs as the rare mineral eskolaite.-Structure and properties:...

 with acetylacetone

Acetylacetone

Acetylacetone is an organic compound that famously exists in two tautomeric forms that rapidly interconvert. The less stable tautomer is a diketone formally named pentane-2,4-dione. The more common tautomer is the enol form. The pair of tautomers rapidly interconvert and are treated as a single...

 (Hacac):

Cr₂O₃ + 6 Hacac → 2 Cr(acac)₃ + 3 H₂O

The complex has idealized D₃ symmetry

Molecular symmetry

Molecular symmetry in chemistry describes the symmetry present in molecules and the classification of molecules according to their symmetry. Molecular symmetry is a fundamental concept in chemistry, as it can predict or explain many of a molecule's chemical properties, such as its dipole moment...

. Like other Cr(III) compounds, it has the d³ configuration, having a quartet ground state. Although it is relatively inert toward substitution, the complex undergoes bromination at the 3-positions of the chelate rings.