Ethylene Dibenzoate Synthesis Lab Report

We started our work with a reference paper, where ethylene di-benzoate(EDB) was taken as sample molecule. We studied the $\beta$-elimination reaction of EDB as a model system in order to follow the thermal degradation of polyethylene terephthalate(PET). In this system the carbon in the ester linkage turns into a nucleophile and interacts with the $\beta$-hydrogen atom of glycol unit. This resulted in the formation of six centred cyclic transition state. In vacuum, the final Gibbs free energy which is the difference between the total energy in the reactant and the transition state was calculated to be 51.1kcal/mol. Potential energy scans (PES) was performed and yielded values like 50.7 kcal/mol for EDB. The values obtained were comparable to

We can observe a saddle point which is undoubtedly a transition state. The energy at this peak was recorded and compared with the reactant energy to find the activation energy of the compound.

\subsection{ Analyzing TZVP and SVP values:}
\label{sec:sec02}

\begin{figure} \includegraphics[width=\textwidth]{tzvp_svp.png} \centering \label{fig: TZVP vs SVP} \caption{ TZVP vs SVP }
\end{figure}

The computational protocol we had consisted of three vital steps, the first step was to submit the job for optimizing the chemical compound at ground level. The second was to perform the geometry scan where we can trace the path followed by the $\beta$ -elimination reaction. The objective of the final step was to submit a job to find out the total enthalpy at the transition state so that activation energy can be calculated. The third job would run only when the geometry scan is

As the value of rate constant for the reaction was known, we replaced it in the equation (4.2) we get the value of A to be 2.24 *10$^{29}$. In order to get the half-lives of all the compounds, the value of A was kept constant. The rate constant was later found in the reaction which in turn leads to determining the half-lives of all other compounds. We established the half-lives of all the compounds and plotted in a graph. A difference of about 50kJ/mol would result in reducing the rate constant by a factor of 10$^8$. Hence, a wide range of half-lives can be observed from 10$^{-17}$ to 10 $^{+29}$