Thermal stability, decomposition enthalpy, and Raman spectroscopy of 1-alkene secondary ozonides

- Decomposition enthalpy of 1-alkene secondary ozonides: from −313 to −347 kJ/mol.
- The decomposition temperature occurs with an onset at 106 °C and peak at 130 °C.
- The activation energy for the ozonide decomposition: 76-86 kJ/mol.
- The thermal decomposition products analyzed by TGA-FTIR and by GC-MS.
- The Raman spectra of secondary ozonides show the O-O stretching at about 823 cm−1.

The synthesis of a series of 1-alkene secondary ozonides was monitored with Raman spectroscopy which is very effective in the detection of the O-O stretching band of the 1,2,4-trioxolane ring. The 1-alkene secondary ozonides thermal decomposition was studied with DSC (differential scanning calorimetry). For all ozonides studied the decomposition onset was found at about 106 °C and the decomposition peak at about 130 °C. The decomposition enthalpy ΔHdec of the secondary ozonides examined was found in the range of −313 to −347 kJ/mol. Despite the considerable amount of heat evolved, the decomposition was not explosive. The decomposition products of 1-octadecene ozonide were studied by TGA-FTIR (thermogravimetric analysis coupled with FT-infrared spectroscopy) and by GC-MS. The main products detected were formic acid and heptadecanal.

1-Alkene ozonides ΔHdec = −314 to −347 kJ/mol. Onset decomposition temperature = 106 °C. Decomposition temperature peak = 131 °C.