Theoretical Study of Absolute Entropy, Entropy of Formation, and Gibbs Energy of Formation of Two Novel...

In this study, we present a solid-state reaction that enables the novel synthesis of diimidetricarboxylic acids (DITAs) in good yields without using harmful solvents. The synthesis route offers advantages, including satisfactory efficiency and easy product purification by sublimation. The reaction utilizes trimellitic anhydride (TMA) with 3,4- and 3,5-diaminobenzoic acid to obtain the desired DITAs. Products were characterized using differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (¹H NMR), and mass spectrometry (MS). The enthalpies of formation in the gas phase of DITAs (Δ _f H°) were calculated, occupying absolute entropies (S°), entropies of formation (Δ _f S°), and Gibbs energies of formation (Δ _f G°). These properties were determined using the hybrid method B3LYP functional and the computational technique machine learning. Our theoretical studies revealed that it is possible to predict thermochemical properties with machine learning as accurately as with density functional theory (DFT).