2,2-Dimethoxy-2-phenylacetophenone

• CAS: 24650-42-8
• Catalog Number: ACM24650428-5
• Category: Main Products
• Molecular Weight: 256.30
• Molecular Formula: C6H5COC(OCH3)2C6H5
• Synonyms: α,α-Dimethoxy-α-phenylacetophenone, Benzil α,α-dimethyl acetal
• IUPAC Name: 2,2-dimethoxy-1,2-diphenylethanone
• SMILES: COC(OC)(C(=O)c1ccccc1)c2ccccc2
• InChI: 1S/C16H16O3/c1-18-16(19-2,14-11-7-4-8-12-14)15(17)13-9-5-3-6-10-13/h3-12H,1-2H3
• InChI Key: KWVGIHKZDCUPEU-UHFFFAOYSA-N
• Boiling Point: 300ºC
• Melting Point: 67-70 °C (lit.)
• Flash Point: >190 °C
• Density: 1.122g/cm³
• Appearance: colourless crystalline
• Application: Photocuring agent
• Assay: 99%
• EC Number: 246-386-6
• Exact Mass: 256.11000
• Features And Benefits: 1. High quality products; 2. Fast delivery; 3. Additional products can be ordered, please contact us for details
• Form: human ... ACHE(43) , BCHE(590) , CES1(1066)
• Hazard Statements: Xi:Irritant
• MDL Number: MFCD00008475
• NACRES: NA.23
• Packaging: Packaging; 50, 250 g in poly bottle
• Physical State: Solid
• PubChem ID: 24851736
• Quality Level: 200
• Safety Description: S36/37-S60-S61
• Stability: Stability Stable, but light-sensitive. Combustible. Incompatible with strong acids, strong oxidizing agents.
• WGK Germany: 2

Case Study

2,2-Dimethoxy-2-phenylacetophenone as Type I Photoinitiator for Photopolymerization of Thick-Section Dental Methacrylate Resins

Mucci, Veronica, et al. Journal of Applied Polymer Science 123.1 (2012): 418-425.

2,2-Dimethoxy-2-phenylacetophenone (DMPA) functions as a Norrish type I photoinitiator that undergoes alpha cleavage under ultraviolet irradiation to generate initiating radicals, enabling rapid photopolymerization of methacrylate dental resins in thick sections without an amine coinitiator.
Experimental Protocol: BisTEG (70:30 bisGMA/TEGDMA) and UDMA resins containing 0.125, 0.25 or 0.5 wt% DMPA are sandwiched between glass plates with a 2 mm spacer and irradiated with a 365 nm light-emitting diode at 95 or 200 mW; conversion is tracked by near-infrared spectroscopy (6165 cm^-1 band) and surface conversion by attenuated total reflectance (1637 cm^-1) at regular intervals up to 100 seconds.
Performance Evaluation: Fast reactions and high conversions are achieved with only 0.25 wt% DMPA, with rate increasing from 0.125 to 0.25 wt% but plateauing at 0.5 wt% owing to light screening. After 5 seconds of irradiation, conversion reaches 0.45 versus 0.2 for the camphorquinone/amine system, and after 100 seconds overall conversion is 0.54 versus 0.57. Although photolysis generates light-absorbing products that screen deeper layers and an induction period appears under oxygen at low intensity, both effects are offset by the higher-intensity source. With a photon absorption efficiency of 286 versus 86 and comparable cure profiles, DMPA is colorless, requires no amine and is attractive for esthetic dental composites.

2,2-Dimethoxy-2-phenylacetophenone as Type I Photoinitiator for Thiol-Ene Photoresins in Optical 3D Printing

Miezinyte, Greta, et al. Rapid Prototyping Journal 25.2 (2019): 378-387.

2,2-Dimethoxy-2-phenylacetophenone (DMPA) acts as a type I photoinitiator that generates primary radicals to drive thiol-ene photocross-linking of acrylated epoxidized soybean oil with benzenedithiols, enabling renewable photoresins for optical 3D printing.
Experimental Protocol: Stoichiometric mixtures of acrylated epoxidized soybean oil (2.7 acrylate groups per triglyceride) and benzene-1,3-dithiol or benzene-1,4-dithiol are prepared with 1-5 mol% photoinitiator, and photocross-linking kinetics are monitored by real-time photorheometry at 24 degrees Celsius under 250-450 nm radiation at 9.3 W/cm²; cast specimens (15 mm diameter, 3 mm thick) are cured with 310 mW/cm² illumination at 10 cm distance and evaluated by Soxhlet extraction, differential scanning calorimetry, thermogravimetric analysis and compression testing.
Performance Evaluation: Storage modulus reaches its highest value in less than one second when the photoinitiator content is 2 mol% or higher, and insoluble fractions of 88-94% (1,3-dithiol) and 72-86% (1,4-dithiol) are obtained, exceeding those with a hydroxy-ketone comparator. Delayed gelation, characteristic of thiol-ene click reactions, yields uniform networks, and swelling in chloroform and toluene decreases with higher initiator content, indicating more cross-links and shorter chains between junction points. Polymers exhibit glass transitions from -17 to 1 degree Celsius and 10% weight-loss temperatures of 337-350 degrees Celsius, with higher compressive modulus, confirming fast, uniform network formation suited to rapid prototyping and additive manufacturing.

2,2-Dimethoxy-2-phenylacetophenone as UV Photoinitiator for Catalyst-Free Thiol-Ene Curing of Silicone Rubber

Xue, Lei, et al. Materials Letters 106 (2013): 425-427.

2,2-Dimethoxy-2-phenylacetophenone (DMPA) serves as a UV photoinitiator whose photolysis generates primary radicals that abstract thiol hydrogens, initiating thiol-ene click cross-linking of vinyl-functional polysiloxanes to produce silicone rubber without heavy-metal catalysts or high temperatures.
Experimental Protocol: A high-molecular-weight polydimethylsiloxane gum (100 phr, methylvinyl siloxane units of 0.16-0.30 mol%) is compounded with 55 phr fumed silica, a mercaptopropyl-functional crosslinker at an equimolar thiol-to-alkene ratio, and 0.1 phr photoinitiator; the compound is molded under 10 MPa at room temperature and cured for 10 minutes by irradiation with a high-voltage mercury lamp centered at 365 nm; tensile, tear, hardness, dynamic mechanical and thermogravimetric properties are then determined.
Performance Evaluation: The cured rubbers are transparent and reach tensile strengths of 5.96-8.36 MPa, tear strengths of 23.26-46.82 kN/m, elongations at break of 498-1083% and Shore A hardness of 40-58, improving with vinyl content. The onset of decomposition exceeds 350 degrees Celsius in both nitrogen and air, and the narrow tan delta transition confirms uniform thiol-ene networks formed by a step-growth mechanism. Because the thiol-ene reaction is insensitive to oxygen, curing proceeds in air without heavy-metal residues, demonstrating an attractive catalyst-free, low-temperature alternative for biomedical and electrical applications.

Custom Q&A

What is the IUPAC name?

The IUPAC name is 2,2-dimethoxy-1,2-diphenylethanone.

What is the molecular weight?

The molecular weight is 256.30.

What is the SMILES notation for the product?

The SMILES notation for the product is COC(OC)(C(=O)c1ccccc1)c2ccccc2.

What is the boiling point?

The boiling point is 300ºC.

What is the melting point?

The melting point is 67-70 °C (lit.).

What is the purity?

The purity is 99%.

What is the density?

The density is 1.122g/cm³.

What is the application?

The product is used as a photocuring agent.

What are some features and benefits?

Some features and benefits are high quality products, fast delivery, and the option to order additional products.

How is the product packaged?

The product is typically packaged in 50 or 250 g in a poly bottle.