Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide

• CAS: 75980-60-8
• Catalog Number: ACM75980608
• Category: Main Products
• Molecular Weight: 348.37
• Molecular Formula: C22H21O2P
• Description: Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO) is a monoacylphosphine oxide based photoinitiator that can be incorporated in a variety of polymeric matrixes for efficient curing and color stability of the resin.
• Synonyms: 2,4,6-Trimethylbenzoylphenyl phosphinate, (Diphenylphosphoryl)(mesityl)methanone, (2,4,6-Trimethylbenzoyl)diphenylphosphine oxide
• IUPAC Name: Diphenylphosphoryl-(2,4,6-trimethylphenyl)methanone
• Canonical SMILES: CC1=CC(=C(C(=C1)C)C(=O)P(=O)(C2=CC=CC=C2)C3=CC=CC=C3)C
• InChI: InChI=1S/C22H21O2P/c1-16-14-17(2)21(18(3)15-16)22(23)25(24,19-10-6-4-7-11-19)20-12-8-5-9-13-20/h4-15H,1-3H3
• InChI Key: VFHVQBAGLAREND-UHFFFAOYSA-N
• Boiling Point: 519.6 ± 60.0 °C
• Melting Point: 88-92ºC
• Flash Point: 268.1ºC
• Density: 1.17 g/cm³
• Appearance: White or cream powder
• Application: TPO can be used in the photo-crosslinking of PMMA composite, which can further be used as a gate insulator in organic thin film transistors (OTFTs). It can also be used in the formation of UV curable urethane-acrylate coatings. It may also be used in the photoinduced reaction for the formation of organophosphine compounds, which potentially find their usage as ligands with metal catalysts and reagents.
• Assay: 97%
• Complexity: 468
• Covalently-Bonded Unit Count: 1
• EC Number: 278-355-8
• Exact Mass: 348.127917g/mol
• Features And Benefits: 1. High quality products; 2. Fast delivery; 3. Additional products can be ordered, please contact us for details
• Formal Charge: 0
• Hazard Codes: Xn
• H-Bond Acceptor: 2
• H-Bond Donor: 0
• Heavy Atom Count: 25
• HS Code: 2931900090
• LogP: 4.76610
• MDL Number: MFCD00192110
• Monoisotopic Mass: 348.127917g/mol
• NACRES: NA.23
• Packaging: Packaging; 10, 50 g in poly bottle
• Physical State: Solid
• PSA: 43.95
• PubChem ID: 24866046
• Quality Level: 200
• Refractive Index: n20/D 1.475(lit.)
• Rotatable Bond Count: 4
• Stability: Stable. Incompatible with strong oxidizing agents.
• UNII: B9EIM2D97X
• WGK Germany: 2
• XLogP3: 5

Case Study

Experiments on photoinitiator systems containing diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide

Miletic, Vesna, et al. Journal of Dentistry 41.10 (2013): 918-926.

Comparison of degree of conversion (DC) of diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO) or anthraquinone/tertiary amine (CQ/Amine) initiated adhesives and their performance with dental drills "Instant" microtensile bond strength (mTBS) of incisal dentin. Experimental counterparts containing TPO as photoinitiator system, experimental G-alkenal bond adhesive formulation and experimental LUB-102 adhesive formulation containing 2 wt% CQ along and 2 wt% tertiary amine as photoinitiator agent system or 2 wt% TPO; the products cured with a dual-wavelength light curing device were measured by Fourier transform infrared spectroscopy (FTIR). The same adhesive formulation was applied to drill-cut mid-coronal dentin of intact human molars. And conduct mTBS test after 1 week of water storage. In addition to being applied in the self-etch (SE) application mode, the adhesive formulations SBU_CQ/amine and SBU_TPO were also applied in the etch and rinse (E&R) mode, both of which were used for DS and mTBS measurements. There were no significant differences in DC for all adhesive formulations except SBU_CQ/Amine_SE and SBU_TPO_SE. For both SBU formulations, the E&R method achieved significantly higher DCs than the SE method. Concerning mTBS, no significant differences were recorded, except for significantly higher mTBS measured for SBU_CQ/Amine_E&R and SBU_TPO_E&R. In self-etching adhesives, photoinitiator TPO can replace CQ/Amine. Cure and "instant" bonding efficiency depends on the application protocol (E&R vs. SE) but not on the photoinitiator system.
SBU_CQ/Amine and its experimental counterpart containing TPO ("SBU_TPO") in which the corresponding photoinitiator has been added to the mixture in the required amount. The one-step self-etching adhesive G-aenial Bond and the experimental adhesive LUB-102 were obtained from their respective manufacturers and did not contain photoinitiators. The photoinitiator is hydroquinone (CQ), the co-initiator is 4-(dimethylamino)ethyl benzoate (EDMAB), and the photoinitiator is diphenyl (2,4,6-trimethylbenzoyl ) phosphine oxide (TPO).

Photoinduced coupling reaction of diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide

Sato, Yuki, et al. Synthesis 49.16 (2017): 3558-3567.

Diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide (TMDPO) is a widely used free radical initiator in polymer chemistry, but less used in organic synthetic chemistry. We focused on the reaction of TMDPO as a phosphorus source with different E-E compounds under photoirradiation, where E-E stands for heteroatom-heteroatom bonds. Interestingly, the cross-coupling reaction between TMDPO and disulfides or diselenides successfully produced thio- or selenophosphinates and thio- or selenoesters, respectively. The synthesis of a series of thio- and selenophosphinates via this photoinduced cross-coupling reaction was demonstrated.
Reaction of diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide (TMDPO) with different E-E compounds containing heteroatom-heteroatom single bonds of elements from groups 13-16 under photoirradiation. When a mixture of TMDPO and diphenyl disulfide (4aa) was irradiated with a xenon lamp through a Pyrex, the photoinduced cross-coupling reaction between TMDPO and 4aa proceeded successfully to afford S-phenyl diphenyl thiophosphinate (5aa) and S-phenyl 2, 4,6-trimethylthiobenzoate (6aa) in good yields. The reaction did not proceed at all in the dark. Using diphenyl diselenide (4ba) instead of 4aa provided selenophenyl diphenyl selenophosphinate (5ba) and selenophenyl 2,4,6-trimethylselenobenzoate (6ba) in excellent yields. Upon irradiation of a mixture of TMDPO and diphenyl ditelluride (4ca), tetraphenyl 2,4,6-trimethyltellurylbenzoate (6ca) was obtained in good yield. However, tetraphenyl diphenyl tellurylphosphinate (5ca) was not detected, most likely because it is unstable under light irradiation. In the case of tetraphenyldiphosphine (4da), tetraphenyldiphosphine monoxide 5da was obtained quantitatively, and diphenyl(2,4,6-trimethylbenzoyl)phosphine (6da) was generated in only 9% yield, with the formation of a complex mixture derived from 2,4,6-trimethylbenzoyl units. In contrast, hexamethyldisilane (4ea), hexaphenyldigermane (4fa), hexabutyldistanane (4ga), and bis(pinacol)diboron (4ha) did not afford the corresponding coupling products. In these reactions, a large amount of E-E compounds remained unreacted, and many byproducts from the photolysis of TMDPO were generated.

Computational chemistry study of diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide

Qin, Hao, et al. Materials Today Communications 35 (2023): 106071.

Acylphosphine oxide-based photoinitiators have been used in digital light processing (DLP) 3D printing slurries to prepare ceramic materials. The study systematically studied the changes from the ground state to the first excited state, energy gap, UV-visible spectrum, excitation energy, absorption wavelength, oscillator strength, etc. after hydrogen atoms were replaced by different electron-donating substituents (-NH2, -OCH3, -OH), substitution positions (ortho, meta, para) and tri-substitution positions (2,4,6 and 3,4,5) through the DMol3 module of Materials Studio. The results show that the order of the electron-donating ability of these four groups is: -NH2>-OCH3>-OH>-H. When the triggering wavelength 𝜆≤425nm, enhancing the electron-donating ability of the substituent and substituting the para position can both increase the oscillator strength and cause the absorption peak to blue-shift. Among them, 4-TPO-NH2, which has the strongest electron-donating ability, substituted at the para position, has the highest oscillator strength (21.5%) and the largest blue-shift (22nm) compared with unsubstituted Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide; when the triggering wavelength 𝜆≥425nm, enhancing the electron-donating ability of the substituent, substituting the para or ortho position of 𝜆, and the three substituents at the 2, 4, and 6 positions are most conducive to improving the oscillator strength and red-shifting the absorption peak.
In order to verify the accuracy and effectiveness of the calculation results, the molecular model of Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide was structurally optimized using functional groups of different densities, and the maximum absorption wavelength was calculated. When the generalized gradient approximation (GGA) of the Perdew-Burke-Ernzerh (PBE) functional group was used for calculation, the difference between the maximum absorption wavelength and the theoretical value was the smallest. Therefore, the GGA PBE basis set will be used in subsequent calculations.

Diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide for 3D printing research

Buchon, Loïc, et al. Journal of Applied Polymer Science 140.47 (2023): e54694.

Photopolymerization 3D printing has attracted much attention due to its ability to achieve very small sizes and high resolution. In the case of recent 3D printers, the preferred light irradiation wavelength is 405 nm, as it is a safe and energy-efficient irradiation. Therefore, in order for 3D printing to work, it is necessary to develop an easy-to-use, stable, and efficient 405 nm wavelength photoinitiator system. To this end, the photochemical properties (triplet energy, bond dissociation energy, cleavage reaction enthalpy, and absorption properties) of several molecules were calculated by molecular modeling, and the most promising compounds were synthesized. Four phosphine oxide photoinitiators (ADPO-1, CPO-2, CPO-3, and FPO-1) were synthesized and characterized. Notably, among the obtained photoinitiators, two of them showed better efficiency in photopolymerization than the commercially available and widely used phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (BAPO) (i.e., (Rp/[M])x100 values of 6.94, 12.95, and 4.93 s for CPO-2, ADPO-1, and BAPO; [M] is the initial acrylate functional concentration). Moreover, one of the synthesized photoinitiators has been successfully used for 3D printing of thermoplastics with potential recycling capabilities. Finally, one of the obtained structures showed lower cytotoxicity than the benchmark structure diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO).
The cytotoxicity of the synthesized photoinitiators was evaluated in human umbilical vein endothelial cells (HUVEC) and human normal hepatocytes (L02) using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. HUVECs were seeded at a density of 8·10-1·10 cells/well in 96-well plates and incubated at 37°C and 5% CO2 for 24 h. Meanwhile, 100 mM diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO) and ADPO-1 stock solutions were prepared in ethanol and then diluted to different concentrations using DMEM (Dulbecco's Modified Eagle Medium)/F12 containing 10% FBS. After incubation with cells for 24, 48, and 72 h, the medium containing TPO or ADPO-1 was removed and subsequently replaced with serum-free medium. Finally, cell viability was determined using the MTT assay.

Custom Q&A

What is the chemical name?

The chemical name is Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide.

What is the molecular formula?

The molecular formula is C22H21O2P.

What is the molecular weight?

The molecular weight is 348.37.

What is the melting point?

The melting point is 88-92ºC.

What is the boiling point?

The boiling point is 519.6 ± 60.0 °C.

What is the purity level?

The purity level is 95%+.

What is the application in PMMA composite?

The product can be used in the photo-crosslinking of PMMA composite, which can further be used as a gate insulator in organic thin film transistors (OTFTs).

What are some features and benefits product?

Some features and benefits product include high quality, fast delivery, and the ability to order additional products.

What is the packaging size product?

The product product is available in 10g and 50g packaging in a poly bottle.

How can the product be used in the formation of UV curable urethane-acrylate coatings?

The product can be used in the formation of UV curable urethane-acrylate coatings by initiating photoinduced reactions for curing.