Trans-1,3,3,3-tetrafluoropropene, also called 1234ze(E), is a new refrigerant that has not yet been well researched. Prof. Max McGillen has found evidence that it has a very high global warming potential especially an indirect one. As such, I studied the ozonolysis of this molecule to determine what products it can generate and their global warming potentials using computational methods. Given the relatively inert C-F bond, a reaction with ozone, the highly reactive triatomic form of oxygen found in the atmosphere, is more likely than electronic excitation. Using first wB97X-D Theory with a cc-pVTZ basis set using the Gaussian Engine and then the W1-F12 composite method in the Molpro engine, the energies of the minima and transition states were found. Due to the sheer amount of time required for some W1-F12 calculations, the energies for the larger ozonides and their transition structures were not determined. Ultimately, the reaction leads to olefins and acetaldehyde oxides. The acetaldehyde oxides go through a series of reactions to generate hydroxyl radical and a carbonyl radical, hydrogen fluoride and carbon dioxide, or carbon monoxide and hypofluorous acid, although the last set is difficult to find transition structures for and needs more research. Some interesting discoveries are that the carbene HCOOF does not appear to exist according to computational models and that the fluoromethanoate with a synperiplanar dihedral angle does not seem to have a transition structure to hypofluorous acid and carbon monoxide but instead one to fluoromethanoic acid. This would contradict Dieter Cremer’s statement that acetaldehyde oxide of a formula RR’COO will decompose into the final products of ROR’ with carbon monoxide and RR’ with carbon dioxide. Finally, my research shows that the formation of carbon dioxide and hydrogen fluoride is favored thermodynamically, meaning that 1234ze(E) definitely has a high global warming potential, though its total impact requires more research.

Ozonolysis of the new refrigerant: trans-1,3,3,3-tetrafluoropropene

ACS Spring 2022

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