Thioformaldehyde S-sulfide (Thiosulfine)

Area of Science:

• Chemical Physics
• Organic Chemistry
• Spectroscopy

Background:

• Matrix isolation spectroscopy is a powerful technique for studying reactive intermediates.
• Pyrolysis of sulfur-containing heterocycles can yield unique molecular structures.

Purpose of the Study:

• To directly identify ylide 1 and its cyclic isomer 2.
• To investigate the thermal decomposition pathway of 1,2,4-trithiolane.

Main Methods:

• High-vacuum pyrolysis of 1,2,4-trithiolane.
• Matrix isolation spectroscopy for trapping and identification of reaction products.

Main Results:

• Direct spectroscopic identification of ylide 1 was achieved.
• The cyclic isomer 2 was successfully isolated and characterized.
• Evidence for a kinetically controlled thermal ring closure mechanism forming the cyclic isomer was obtained.

Conclusions:

• Matrix isolation spectroscopy is suitable for the direct identification of transient ylides and their isomers.
• The pyrolysis of 1,2,4-trithiolane provides a route to ylides and cyclic sulfur compounds.
• The formation of the cyclic isomer is governed by kinetic control during thermal ring closure.