Sulfonium diphenyl[(phenylthio)phenyl]hexafluorophosphate

• CAS: 75482-18-7
• Catalog Number: ACM75482187
• Category: Main Products
• Molecular Weight: 516.50
• Molecular Formula: C₂₄H₁₉F₆PS₂
• Synonyms: sulfonium diphenyl[(phenylthio)phenyl] hexafluorophosphate; Sulphonium diphenyl[(phenylthio)phenyl]hexafluorophosphate; Mixed of Triaryl-sulfonium Hexafluoro-Phosphate Salt
• IUPAC Name: Diphenyl[(phenylthio)phenyl]sulfonium hexafluorophosphate
• Exact Mass: 516.05700

Case Study

Diphenyl[4-(phenylthio)phenyl]sulfonium Hexafluorophosphate as a Cationic Photoinitiator in Visible-Light Polymerization

Jia, Xiaoqin, et al. Polymer Chemistry 10.17 (2019): 2152-2161.

Diphenyl[4-(phenylthio)phenyl]sulfonium hexafluorophosphate (SON) is a sulfonium salt photoinitiator that, when combined with diphenyl sulfone-based A-π-D-π-A dyes (e.g., P-DSO, T-DSO), enables efficient cationic ring-opening polymerization of epoxides under 405 nm LED irradiation via a photoinduced electron-transfer mechanism.
Experimental Protocol: Two-component systems (0.1 wt% DSO + 1 wt% SON) were formulated with epoxy resin E51. Conversion was monitored by real-time FTIR. Cyclic voltammetry determined oxidation potentials; free energy changes (ΔG) for electron transfer were calculated. Steady-state photolysis and electron spin resonance spin trapping (using PBN) were performed.
Performance Evaluation: The P-DSO/SON system achieved a final epoxy group conversion of ≈60% after 60 s irradiation, significantly higher than the reference ITX/SON system (≈35%). The calculated ΔG for the P-DSO/SON system was -1.07 eV, confirming thermodynamic feasibility of electron transfer from excited DSO to SON. Spin trapping experiments with PBN detected phenylthiyl radical adducts, confirming radical generation. In free radical polymerization of acrylates, the DSO/SON systems were less efficient than the corresponding DSO/iodonium systems, consistent with the less negative reduction potential of SON.
Conclusion: SON serves as an effective co-initiator for cationic polymerization under visible LED light when paired with appropriate sensitizers, offering a lower-toxicity alternative to iodonium salts in certain applications.

Diphenyl[4-(phenylthio)phenyl]sulfonium Hexafluorophosphate as a Cationic Photoinitiator with Intrinsic Flame-Retardant Properties

Li, Yong-Jie, et al. Journal of Applied Polymer Science 131.7 (2014).

Diphenyl[4-(phenylthio)phenyl]sulfonium hexafluorophosphate (In-S) is a cationic photoinitiator for the UV-curing of cycloaliphatic epoxides. Beyond initiating polymerization, the sulfur atom in its structure confers inherent flame retardancy to the cured resin, and it can be combined with silicon-/phosphorus-containing additives for enhanced performance.
Experimental Protocol: In-S (2-4 wt%) was mixed with ERL4221 epoxy resin, with or without the flame-retardant additive DOPO-SiD (P content 1.0-2.4 wt%). Formulations were UV-cured under a high-pressure Hg lamp (10 min, 1 mW/cm²) followed by thermal post-cure (120 °C, 30 min). Limiting oxygen index (LOI), UL-94 vertical burning, and thermogravimetric analysis (TGA) were performed.
Performance Evaluation: In-S alone increased the LOI of cured epoxy from 18.2 (neat resin) to 22.2 at 4 wt% loading. When 4 wt% In-S was combined with 2 wt% P (as DOPO-SiD), the LOI reached 24.8 and the UL-94 rating improved to V-2. The DOPO-SiD additive effectively prevented molten dripping during combustion. TGA showed the onset decomposition temperature of In-S/ERL4221 at 358 °C (neat resin: 316 °C), and char residue was 3.0 wt% at 800 °C. The combination of In-S with DOPO-SiD gave better flame retardancy than In-S alone, though less char formation than when using the iron-based photoinitiator In-Fe.
Conclusion: In-S serves a dual role as a cationic photoinitiator and a flame-retardant promoter, making it suitable for UV-curable epoxy coatings requiring fire resistance.

Custom Q&A

What is the molecular formula of the compound?

The molecular formula is C24H19F6PS2.

What are the synonyms for the compound?

The synonyms for the compound are Diphenyl[4-(phenylthio)phenyl]sulfonium hexafluorophosphate and Diphenyl(4-phenylthio)phenylsufonium hexafluorophosphate.

What is the molecular weight of the compound?

The molecular weight is 516.5 g/mol.

What is the parent compound of the compound?

The parent compound is diphenyl[4-(phenylthio)phenyl] sulfonium.

What are the component compounds of the compound?

The component compounds are sulfonium, diphenyl[4-(phenylthio)phenyl]- and hexafluorophosphate.

What is the IUPAC name of the compound?

The IUPAC name is diphenyl-(4-phenylsulfanylphenyl)sulfanium;hexafluorophosphate.

What is the InChI of the compound?

The InChI is InChI=1S/C24H19S2.F6P/c1-4-10-20(11-5-1)25-21-16-18-24(19-17-21)26(22-12-6-2-7-13-22)23-14-8-3-9-15-23;1-7(2,3,4,5)6/h1-19H;/q+1;-1.

What is the InChIKey of the compound?

The InChIKey is MUVYOKJVJZFJTI-UHFFFAOYSA-N.

What is the canonical SMILES of the compound?

The canonical SMILES is C1=CC=C(C=C1)SC2=CC=C(C=C2)[S+](C3=CC=CC=C3)C4=CC=CC=C4.F[P-](F)(F)(F)(F)F.

What is the topological polar surface area of the compound?

The topological polar surface area is 26.3 Ų.