Ultrasonic cleavage of thioethers

Area of Science:

• Chemical Kinetics
• Physical Chemistry
• Sonochemistry

Background:

• Thioethers are organic compounds containing sulfur.
• Understanding their behavior under ultrasonic irradiation is crucial for synthetic chemistry.
• Previous studies have explored sonolysis of various organic molecules.

Purpose of the Study:

• To investigate the sonolytic products and reaction rates of thioethers.
• To explore the influence of temperature on thioether sonolysis.
• To correlate diphenylpicrylhydrazyl (DPPH) trapping rates with thioether sonochemical activity.

Main Methods:

• Sonolysis of various thioethers (CS2, lower sulfides, thiophene, diallyl sulfide, diethyl disulfide, dipropyl disulfide) at normal and low temperatures.
• Analysis of sonolytic products using techniques like gas chromatography and mass spectrometry.
• Quantification of DPPH (diphenylpicrylhydrazyl) radical trapping rates.

Main Results:

• Common sonolysis products include CS2, lower sulfides, thiophene, and sulfurized species.
• Hydrocarbons, aldehydes, and SO2 were identified as products under specific conditions.
• A strong correlation was observed between DPPH trapping rates and thioether vapor pressures.
• Lower vapor pressure correlated with higher sonolytic reaction rates.

Conclusions:

• The primary sonochemical process involves C-S or S-S bond cleavage followed by recombination and rearrangement.
• DPPH trapping serves as a reliable indicator for the sonolytic potential of thioethers.
• Thioether sonolysis exhibits similarities to pyrolysis, suggesting related reaction mechanisms.