Chromium(III) acetylacetonate

• CAS: 21679-31-2
• Catalog Number: ACM21679312-5
• Category: Main Products
• Molecular Weight: 352.34g/mol
• Molecular Formula: C15H24CrO6
• Synonyms: Chromium(III) 2,4-pentanedionate
• IUPAC Name: chromium;(E)-4-hydroxypent-3-en-2-one
• SMILES: CC(=CC(=O)C)O.CC(=CC(=O)C)O.CC(=CC(=O)C)O.[Cr]
• InChI: InChI=1S/3C5H8O2.Cr/c3*1-4(6)3-5(2)7;/h3*3,6H,1-2H3;/b3*4-3+
• InChI Key: MJSNUBOCVAKFIJ-MUCWUPSWSA-N
• Appearance: Solid
• Storage: Store below +30°C.
• Complexity: 380
• Covalently-Bonded Unit Count: 4
• EC Number: 244-526-0
• Exact Mass: 352.097793g/mol
• Formal Charge: 0
• H-Bond Acceptor: 6
• H-Bond Donor: 3
• Heavy Atom Count: 22
• Monoisotopic Mass: 352.097793g/mol
• Rotatable Bond Count: 3

Case Study

Deposition of Chromium Oxide (Cr₂O₃) Thin Films via Atmospheric-Pressure CVD Using Chromium(III) Acetylacetonate

Maruyama, Toshiro, and Hisao Akagi. Journal of the Electrochemical Society 143.6 (1996): 1955-1958

This study investigated the use of chromium(III) acetylacetonate [Cr(C₅H₇O₂)₃] as a precursor for depositing chromium oxide (Cr₂O₃) thin films via atmospheric-pressure chemical vapor deposition (CVD). The precursor was heated to 215°C to generate vapor, which was entrained in nitrogen carrier gas and mixed with air before being introduced into a closed-tube reactor. Borosilicate glass and gold-coated glass substrates were used, with reaction temperatures ranging from 400 to 500°C. Films deposited above 400°C were shiny and smooth, in contrast to the rough, powdery films from chromium hexacarbonyl precursor. X-ray diffraction confirmed polycrystalline Cr₂O₃ with a hexagonal structure at temperatures above 450°C, while films at 400°C were amorphous. Optical characterization revealed significant solar absorptance (0.57 for amorphous, 0.64 for polycrystalline) and low thermal emittance (0.12-0.24 at 25-300°C), resulting in high selectivity (a/ε ratio up to 5.1). These properties make the films suitable for solar thermal energy conversion, as they efficiently absorb solar energy while minimizing thermal emission.The in vitro deposition and characterization were conducted through controlled CVD experiments. Precursor vaporization and gas flow rates were regulated (nitrogen carrier gas 595-598 cm³/min, air 2-5 cm³/min). Film morphology was analyzed via scanning electron microscopy, composition via X-ray photoelectron spectroscopy, and crystallinity via X-ray diffraction with Cu Kα radiation. Optical properties were measured using UV-VIS-NIR spectrophotometry (0.19-3.2 μm) and Fourier transform infrared spectroscopy (1.92-25 μm). Solar absorptance was calculated using solar spectral irradiance data, and thermal emittance via Planck's spectral distribution. All experiments were performed in triplicate, with statistical analysis of deposition rates and optical parameters to confirm reproducibility.

Electrochemical Performance of Chromium(III) Acetylacetonate as Active Species in Non-Aqueous Redox Flow Batteries

Liu, Qinghua, et al. Electrochemistry Communications 12.12 (2010): 1634-1637

This study evaluated chromium(III) acetylacetonate [Cr(acac)₃] as the active species in a single-metal non-aqueous redox flow battery (RFB), with tetraethylammonium tetrafluoroborate (TEABF₄) as the supporting electrolyte and acetonitrile (CH₃CN) as the solvent. Cyclic voltammetry (CV) analysis revealed four quasi-reversible redox couples (Crᵢ/ Crᵢᵢ, Crᵢᵢ/ Crᵢᵢᵢ, Crᵢᵢᵢ/ Crᵢᵥ, Crᵢᵥ/ Crᵥ) within the solvent's stable potential window. The one-electron disproportionation of neutral Cr(acac)₃ yielded a high cell potential of 3.4 V, significantly higher than aqueous RFB systems (~1.26 V). The Crᵢᵢᵢ/ Crᵢᵥ couple exhibited comparatively slower kinetics, while the other couples showed favorable reversibility. The diffusion coefficient of Cr(acac)₃ in the electrolyte was estimated to be 5.0-6.2 × 10⁻⁷ cm² s⁻¹ at room temperature. Charge-discharge tests in an H-type glass cell (anion-exchange membrane separator) achieved stable coulombic efficiencies of 53-58% and energy efficiencies of 21-22% after 5 cycles, with charge voltages of 4.0-4.3 V and discharge plateaus at ~2.2 V and ~1.2 V. These studies demonstrate that Cr(acac)₃ is a promising active species for high-potential non-aqueous RFBs, suitable for grid-level energy storage.The in vitro electrochemical characterization was conducted through systematic CV and charge-discharge experiments. The electrolyte was prepared with 0.05 M Cr(acac)₃ and 0.5 M TEABF₄ in anhydrous CH₃CN. CV measurements were performed using a glassy carbon working electrode, Ag/Ag⁺ reference electrode, and graphite counter electrode, with scan rates ranging from 10 to 500 mV s⁻¹. Diffusion coefficients were calculated using Randles-Sevcik and irreversible redox equations. Charge-discharge tests were carried out in an argon-filled glove box with galvanostatic currents (1.0 mA charge, 0.1 mA discharge), cycling between 0% and 50% theoretical state of charge. The anion-exchange membrane was pre-conditioned in electrolyte for 22+ hours. All experiments were performed at room temperature, with statistical analysis of CV peak currents, potentials, and charge-discharge efficiency data.

Thermal Transformations and Surface Interaction of Chromium(III) Acetylacetonate on Silica

Babich, Igor V., et al. Journal of Colloid and Interface Science 189.1 (1997): 144-150

This study investigated the chemical modification of silica surfaces with chromium(III) acetylacetonate [Cr(acac)₃] via gas-phase deposition at 190°C, focusing on surface interaction mechanisms and thermal transformations. Fumed silica was pretreated at 200, 400, or 800°C to modulate surface hydroxyl group content, then exposed to Cr(acac)₃ vapor. FTIR spectroscopy confirmed hydrogen bonding between silica surface hydroxyl groups (3750 cm⁻¹ band) and the quasi-π-electron system of Cr(acac)₃'s acac ligands, with no loss of acac ligands (acac/Cr ratio ~3). Chromium loading decreased with higher pretreatment temperatures: 0.83 atoms/nm² (200°C), 0.69 atoms/nm² (400°C), and 0.56 atoms/nm² (800°C). Thermal analysis (TGA, TPO) revealed ligand substitution and oxidation: at 230°C (for 200°C-pretreated silica), adsorbed water hydrolyzed acac ligands; at 270°C, surface hydroxyl groups replaced two hydrogen-bonded acac ligands; at 340°C, residual acac ligands oxidized, converting Cr³⁺ to Cr⁶⁺. These studies demonstrate that Cr(acac)₃ interacts with silica via hydrogen bonding, forming thermally responsive surface species suitable for supported catalyst preparation.The in vitro characterization was conducted through systematic surface modification and analytical techniques. Silica pretreatment was performed under nitrogen flow for 2 hours to control hydroxyl group density. Cr(acac)₃ deposition was confirmed by color change (colorless to greenish) and iodometric analysis of chromium content. FTIR spectra (400-4000 cm⁻¹) were recorded in diffuse reflectance and transmittance modes to analyze ligand vibrations and hydroxyl group interactions. Thermal transformations were studied via TGA (30-500°C, 10°C/min) in air (oxidizing) or nitrogen (inert) atmospheres, and TPO (6% O₂ in Ar) to monitor oxygen consumption during ligand oxidation. Surface coverage was calculated using molecular cross-sectional area (0.63 nm²) of Cr(acac)₃. All experiments were performed in triplicate, with statistical analysis of chromium loading and thermal decomposition temperatures.

Simultaneous Determination of Chromium(III) Acetylacetonate, Cr(III), and Cr(VI) in Water via Ion-Exchange Disk Extraction and Metal Furnace Atomic Absorption Spectrometry

Kamakura, Nao, et al. Spectrochimica Acta Part B 93 (2014): 28-33

This study developed a method for the separate and simultaneous determination of chromium(III) acetylacetonate [Cr(acac)₃], inorganic Cr(III), and toxic Cr(VI) in water using cation-exchange (CED) and anion-exchange (AED) extraction disks combined with metal furnace atomic absorption spectrometry (MFAAS). A 100 mL water sample adjusted to pH 5.6 was passed through a CED placed on an AED: Cr(acac)₃ and Cr(III) were adsorbed on the CED, while Cr(VI) was retained on the AED. Cr(acac)₃ was eluted from the CED with 50 mL carbon tetrachloride, followed by elution of Cr(III) with 3 mol L⁻¹ nitric acid; Cr(VI) was eluted from the AED with the same nitric acid. FT-IR spectroscopy confirmed the eluted analyte as Cr(acac)₃. The method exhibited good linearity for Cr(acac)₃ (0.1-1 ng, r=0.9990) with a detection limit of 20 pg. Spike tests in tap water, rainwater, and bottled drinking water (50 μg L⁻¹ of each species) yielded recoveries of 96.0%-107%, with relative standard deviations <7.6%. Cr(acac)₃ was stable and unaffected by humic acid or seawater matrices, unlike Cr(III) and Cr(VI) which showed reduced recoveries in these matrices. These studies demonstrate that the method is reliable for speciation analysis of Cr(acac)₃ and inorganic chromium in environmental and drinking water.The in vitro analytical method was validated through systematic optimization and validation experiments. Disks were conditioned with methanol, deionized water, and nitric acid before use. Sample pH was optimized to 5.6 to ensure maximum adsorption of all species. Elution solvents were selected based on solubility: carbon tetrachloride for Cr(acac)₃ (99.1% recovery) and nitric acid for inorganic chromium (98.4% recovery for both Cr(III) and Cr(VI)). MFAAS operating conditions included a tungsten board atomizer, Cr hollow cathode lamp (357.9 nm), and argon-hydrogen carrier gases, with atomization at 2300°C. Calibration was performed using Cr(acac)₃ standard solutions, validated with a certified reference material (CRM) for Cr(III) (JSAC 0302-3). Matrix effects were evaluated using artificial freshwater, seawater, industrial wastewater, and humic acid solutions. All experiments were performed in triplicate, with statistical analysis of recovery rates and detection limits to confirm method accuracy and precision.

Custom Q&A

What is the molecular formula of Tris(2,4-pentanedionato)chromium(III)?

The molecular formula of Tris(2,4-pentanedionato)chromium(III) is C15H21CrO6.

What is the molecular weight of Tris(2,4-pentanedionato)chromium(III)?

The molecular weight of Tris(2,4-pentanedionato)chromium(III) is 349.32 g/mol.

What is the IUPAC name of Tris(2,4-pentanedionato)chromium(III)?

The IUPAC name of Tris(2,4-pentanedionato)chromium(III) is chromium(3+);(Z)-4-oxopent-2-en-2-olate.

What is the InChI of Tris(2,4-pentanedionato)chromium(III)?

The InChI of Tris(2,4-pentanedionato)chromium(III) is InChI=1S/3C5H8O2.Cr/c3*1-4(6)3-5(2)7;/h3*3,6H,1-2H3;/q;;;+3/p-3/b3*4-3-.

What is the InChIKey of Tris(2,4-pentanedionato)chromium(III)?

The InChIKey of Tris(2,4-pentanedionato)chromium(III) is JWORPXLMBPOPPU-LNTINUHCSA-K.

What is the canonical SMILES of Tris(2,4-pentanedionato)chromium(III)?

The canonical SMILES of Tris(2,4-pentanedionato)chromium(III) is CC(=CC(=O)C)[O-].CC(=CC(=O)C)[O-].CC(=CC(=O)C)[O-].[Cr+3].

What is the CAS number of Tris(2,4-pentanedionato)chromium(III)?

The CAS number of Tris(2,4-pentanedionato)chromium(III) is 21679-31-2.

How many hydrogen bond donor counts does Tris(2,4-pentanedionato)chromium(III) have?

Tris(2,4-pentanedionato)chromium(III) has 0 hydrogen bond donor counts.

How many hydrogen bond acceptor counts does Tris(2,4-pentanedionato)chromium(III) have?

Tris(2,4-pentanedionato)chromium(III) has 6 hydrogen bond acceptor counts.

How many rotatable bond counts does Tris(2,4-pentanedionato)chromium(III) have?

Tris(2,4-pentanedionato)chromium(III) has 3 rotatable bond counts.