Solubility of 2,4-diamino-6-(4-pyridyl)-1,3,5-triazine in tetrahydrofuran and alcohols between 288.15 K and 318.15 K

Abstract

2,4-diamino-6-(4-pyridyl)-1,3,5-triazine (DAPT) was synthesized and analyzed by nuclear magnetic resonance and Fourier transform infrared spectroscopy, thermogravimetric and elemental analysis techniques as well as by high-resolution transmission electron microscopy. DAPT solubility (in tetrahydrofuran, methanol, ethanol, n-propanol, and isopropanol) in the 288.15–318.15 K range was measured using the static analytical technique. We also performed quantum chemical calculations using Gaussian 09 and determined influence of solvent polarity and solute-solvent interactions on DAPT solubility. Experimental results were treated by modified Apelblat and Buchowski-Ksiazaczak ( λh ) equations as well as by the Wilson and nonrandom two-liquid (NRTL) models. All four models showed excellent agreement. This study provides valuable data for the purification of DAPT at the preferential crystallization procedure. • The solubilities of 2,4-diamino-6-(4-pyridyl)-1,3,5-triazine in five different solvents have been obtained. • The interaction energies between solute and solvents were calculated by Density functional theory (DFT). • The experimental solubility data of 2,4-diamino-6-(4-pyridyl)-1,3,5-triazine were correlated by four thermodynamic models.